Buying eBay lots to resell on Amazon: how to price a bundle unit by unit

Last checked November 2, 2026

A lot on eBay can lower your cost per unit, and it can also hide the reasons it is cheap. The sums are the same as for a single item, but they have to be done per unit, with an allowance for units that turn out to be missing, damaged or not what the title says.

This guide walks through five steps with an invented example, in US dollars. The numbers are there to show the method. They are not typical results and not a promise about any product.

Short answer

Divide the whole cost of the lot, including shipping and prep, by the number of units you expect to be able to sell, not the number in the title. Compare that per-unit cost with what one unit earns on Amazon after fees. If it clears your profit line even with one or two units lost, the lot deserves a closer look.

Step 1: read the quantity and the contents

Titles say “lot of 6” or “bundle” and leave the detail to the description. Read all of it before you do any math.

How many units are there, and are they all the same model? A mixed lot needs a separate sum for each model.
Is each unit complete: box, accessories, charger, manual? Amazon buyers expect what the Amazon listing says.
Are the units new, used, or untested? The condition decides whether you can list them at all.

If the description is thin, ask the seller for a photo of every unit. A seller who cannot show the units has told you something.

Step 2: match each unit to the right Amazon item

Find the model number on the units in the photos or the item details, and match it to one Amazon listing, suffix included. A lot of near-identical models can include versions with different battery counts or accessories, which are separate Amazon items at different prices.

For power tools, our model number guide shows where to find the number and how suffixes change the product.

Step 3: price the lot per unit

Add the full cost of the lot first, then divide. Here is an invented example: six identical units, new in box. The same unit sells on Amazon for 45.00.

Invented example, US dollars

Amazon price per unit       45.00
- referral fee (15%)          6.75
- fulfillment fee             4.80
= proceeds per unit          33.45

lot price (6 units)         120.00
+ shipping to you            18.00
+ prep (1.00 a unit)          6.00
= lot cost                  144.00

cost per unit   = 144.00 / 6 = 24.00
profit per unit = 33.45 - 24.00 = 9.45
return          = 9.45 / 24.00 = 39.4%

The 15% referral fee is an example only. Use Amazon's fee preview for your item. For the full list of cost lines, see the profit math guide.

Step 4: allow for units you cannot sell

Now assume one of the six turns out to be missing a part or arrives damaged. You still paid 144.00, but you can sell five.

cost per sellable unit = 144.00 / 5 = 28.80
profit per unit        = 33.45 - 28.80 = 4.65
return                 = 4.65 / 28.80 = 16.1%

The return fell from 39.4% to 16.1% because of one lost unit. If your line is 20%, the lot passes with six good units and fails with five. Decide before you bid how many units you can afford to lose, and bid so the lot still clears your line at that count.

Also keep in mind that adding six units to the market can push the Amazon price down while you sell them. Run the sum again at a lower Amazon price before you commit.

Step 5: check the seller and the return terms

Lots are where a clear return policy matters most, because a missing unit becomes a dispute. Before you buy, check that the seller accepts returns for an item not as described, read their recent feedback, and keep the listing photos and description. Buy by hand and keep a record of the listing, the price and the date for each lot.

Our step-by-step sourcing guide covers condition rules, approvals and record keeping in more depth.

Where software helps with lots

MarginPing watches new eBay listings for power tools and tool kits you already sell. It matches by model number and by UPC when the listing has one, and it reads kit versus bare tool and lot size, so a bundle is compared per unit rather than as one item. It shows a match confidence score, works out estimated Amazon fees and profit, and sends a Telegram message only when the listing clears your profit line.

Amazon prices and fee estimates refresh several times a day, and no Amazon connection is needed. Reading a lot's contents and judging the seller stay with you, and it never buys, bids, or messages a seller.

MarginPing is in final testing and not open for signups yet. At launch: $100 a month for up to 20 products. Starts with a free 7-day trial, no card needed, when we open. See eBay to Amazon alerts for how to set up the alerts.

Want lots priced per unit for you?

Tell us what you sell and roughly how many products. We invite power tool sellers as early access spots open.

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Questions

Are eBay lots a good way to source for Amazon?

They can be, when the lot is a single model you can match exactly and the per-unit cost clears your profit line even after losing a unit or two. A mixed or vague lot is harder to price and carries more risk.

How do I price a mixed lot?

Split it by model, match each model to its own Amazon item, and run the sum for each. Spread the shared costs, such as shipping to you, across the units by count or by value.

How many units should I assume are unsellable?

There is no standard figure. Use your own history, and decide how many units the lot can lose before it drops below your profit line. Bid at a price that still works at that count.

Does MarginPing handle lots?

For power tools and tool kits, it reads lot size from the eBay listing and compares per unit. You still read the description and judge the seller before you buy.