How Many Amazon Units Should You Buy? Smart Strategies for Online Arbitrage Success

Staff
Jul 2
6 min read

Updated: Aug 19

Every seller, from novices to seasoned pros, must make the crucial decision every day: how many Amazon products to purchase. Making the correct choice could make the difference between making money and losing it, whether you're scaling your Amazon business or entering Online Arbitrage (OA). Buy too many units, and a price tank could wipe out your margins. Buy too few, and you’ll kick yourself for leaving money on the table. At FBA Zodiac, we empower sellers with data on our Online Arbitrage Leads List, but the question remains: how do you determine the right quantity?

Every situation is unique, shaped by your risk tolerance, capital, and market dynamics. In this post, I’ll share common-sense strategies to help you decide how many units to buy, leveraging our proprietary MAPS metric (Monthly Average Per Seller) and practical tips to optimize your inventory management. Let’s dive in and make your next lead purchase a confident one.

Step 1: Start with the Minimum for Free Shipping (or Skip It)

Your first course of action when assessing an Amazon FBA lead or retail arbitrage deal should be to purchase the bare minimum needed to qualify for free shipping, or to pass on the offer completely. Why? This reduces your risk while guaranteeing that you fulfil supplier requirements (such as wholesale minimums or Target's free shipping on orders over $35). Free shipping maintains your ROI by lowering your cost per product. It also mitigates your risk if prices go down while preserving capital for future buys. If you find yourself running out of capital, this is an excellent tactic to employ.

When to Stick to the Minimum:

Uncertain Demand: If the product’s sales velocity is unclear or the niche is volatile (e.g., seasonal items post-holiday), buying the minimum protects you from overstocking.
New Sellers: If you’re just starting with Online Arbitrage, limited capital makes small buys safer while you test the waters.
High Competition: If the lead shows many FBA sellers (e.g., 20+), price wars are likely, so sticking to the minimum reduces exposure. Something may be profitable, but it looks like there's a higher chance it'll go down in price in the future. Buying smaller amounts lets you enter and exit quickly. If it doesn't go down in price, you can buy it again. If it does go down, you've capped your losses.
Low MAPS: The product may remain unsold, tying up capital, if the Monthly Average Per Seller (described below) is too low (e.g., <5 units/month).

Step 2: Leverage the MAPS Metric for Smarter Buying

At FBA Zodiac, our Online Arbitrage Leads List includes two critical metrics for every lead: estimated monthly sales and number of FBA sellers. These power our proprietary MAPS metric—Monthly Average Per Seller—a rule-of-thumb guide to estimate how many units you can expect to sell per month.

How MAPS Works: Formula: MAPS = Total Monthly Sales ÷ Number of FBA Sellers.

Example: If a product has 100 monthly sales and 10 FBA sellers, the MAPS is 10 units per seller per month. This means you can reasonably expect to sell ~10 units monthly, assuming equal competition.

Why It Matters: MAPS helps you avoid overbuying, preventing excess inventory that sits in Amazon’s warehouses, racking up FBA storage fees.

Using MAPS to Decide Quantity: Buy 1–2 Months’ Worth: For a MAPS of 10 units/month, buying 10 units sets and defines your goal of selling through in a month.

Adjust for Risk Tolerance: Low Risk: Buy 1 month’s worth (10 units) if you’re cautious or the product has price volatility. Our leads have price stability, one of the most critical aspects of good leads to buy.

High Risk: Buy 2–3 months’ worth (20–30 units) if the MAPS is strong, competition is low, and ROI is high (e.g., 50%+).

Monitor Trends: If MAPS drops (e.g., more sellers join), reduce future buys. Our FBA Zodiac leads update regularly to reflect these shifts.

Step 3: When to Buy More Than the Minimum

While the minimum buy is a safe default, certain scenarios justify purchasing more units. Here’s when to scale up your order, based on market signals and lead data:

A. Unbeatable Sale Prices: If a product is on a deep discount (e.g., 40% off retail) and you can’t replenish at that price, buying more locks in your margins.

Tip: Check the lead’s Keepa chart to confirm the sale price is rare. Buy 1 month's worth (per MAPS) to capitalize.

B. Low Competition, High MAPS:You can increase sales before rivals join if the lead displays a high MAPS (e.g., 20 units/month) and few FBA sellers (e.g., 2–5).

C. High ROI, Slow Movers:Some products have low MAPS (e.g., 2–5 units/month) but high ROI (e.g., 80–100%). These are worth buying if you can afford to wait for the sales to come. Strategy: Buy 3–6 months’ worth (6–30 units) and diversify across multiple slow movers to spread risk. Our FBA Zodiac leads highlight these opportunities with ROI filters.

D. Seasonal or Trending Products

If a lead relates to a trending niche (e.g., workout gear in January) or seasonal demand (e.g., Halloween costumes in August), buy adequate inventory to handle peak sales (e.g., 3x MAPS for 1 month). Use Google Trends or our lead insights to confirm demand spikes.

Step 4: Strike a balance between capital and risk tolerance

Every purchase is influenced by your available funds and risk tolerance. Here's how to match your approach:

1. Limited Capital/Low Risk (e.g., < $5,000):

Limit your purchases to qualify for free shipping.
Pay attention to low-competition, high-MAPS leads (e.g., <5 sellers, 10+ units/month).
Spread your exposure among five to ten different goods.

2. Moderate Risk/Medium Capital (e.g., $5,000–$20,000):

Buy 1–2 months’ worth based on MAPS.
Mix fast movers (high MAPS) with high-ROI slow movers.
Reinvest profits to scale gradually.

3. High Risk/High Capital (e.g., >$20,000):

Buy 2–4 months’ worth for strong leads.
Take calculated risks on deep discounts or trending products.
Use FBA Zodiac’s premium filters to identify high-ROI, low-competition leads.

Pro Tip: Always leave a cash buffer (20–30% of capital) for unexpected costs (e.g., PPC ads, storage fees, or new leads). Overbuying ties up funds, limiting your ability to pivot.

Step 5: Avoid Common Pitfalls

Even with MAPS and smart strategies, mistakes happen. Here’s what to watch for:

Overbuying on Hype: A hot product with 200 sales/month and 20 sellers (MAPS = 10) may seem tempting, but new sellers can tank prices. Buy conservatively (10–20 units) and monitor.
Ignoring Storage Fees: Slow movers with low MAPS (e.g., 2 units/month) cost more to store, especially during Q4 ($2.40/cubic foot). Calculate total ROI with fees included.
Chasing Low ROI: A product with 50 sales, 5 sellers (MAPS = 10), and 10% ROI isn’t worth tying up capital. Prioritize leads with 30%+ ROI, as flagged in our leads list.
Neglecting Replenishment: If a supplier restocks at higher prices, underbuying costs you profits. Check FBA Zodiac’s supplier data to gauge restock reliability.

Why MAPS and FBA Zodiac Make the Difference

Our Online Arbitrage Leads List at FBA Zodiac isn’t just a list—it’s a data-driven tool designed to simplify your buying decisions. Every lead includes:

Estimated Monthly Sales: Based on Amazon’s Best Sellers Rank and historical data
FBA Seller Count: Real-time competitor insights.
MAPS Metric: Your shortcut to sizing buys correctly.
ROI and Keepa Charts: Spot deep discounts and price trends.
Supplier Links: Streamline sourcing with free shipping options.

By combining MAPS with your risk tolerance, you can buy confidently, whether it’s the minimum for free shipping or a larger order for a high-ROI gem. Our leads are tailored for Amazon FBA sellers, from beginners to veterans, ensuring you maximize profits while minimizing risk.

Final Thoughts: Buy Smart, Profit Big

Deciding how many Amazon FBA leads or best retail arbitrage items to buy is both art and science. With strategies that help you increase Amazon sales, you can make your online arbitrage efforts more profitable. Start with the minimum for free shipping, lean on the MAPS metric (e.g., 10 units/month per seller), and scale up for deep discounts, low competition, or high-ROI slow movers. Align your buys with your risk tolerance and capital, and always diversify to avoid overexposure.

With FBA Zodiac’s Online Arbitrage Leads List, you have the data to make informed decisions, turning leads into profits.

Ready to take control of your FBA business? Join FBA Zodiac today and access our premium leads to find your next winning product. Share your buying strategies in the comments below—what’s your go-to approach for sizing orders?