Buying LEGO sets on eBay to sell on Amazon

Why the set number is the match key

Every LEGO set carries a set number printed on the box, usually four to six digits, such as 75192. Many eBay listings put it in the title or the item details, and many show a UPC. Those identifiers tie a listing to one specific Amazon item instead of a guess from the title.

Sealed, opened and everything in between

Amazon lists new sets and used sets as separate offers, and buyers who pay for new expect a factory-sealed box. Check the condition field and the photos together. Sellers often write "new" for a box that was opened once, or "sealed" for a set with the bags still inside a box that has been cut open.

• Factory sealed: the box shows its original seals. Look for torn flaps, tape, and dents that suggest the box was opened and closed again.
• Opened, bags sealed: the set is complete but the box is not new. It is not the item a new-condition offer promises.
• Opened and built, or loose: a different item entirely, and one you cannot verify as complete from photos.

Retired sets add one more check: a sealed box can carry older packaging, and Amazon may list it under a different item than the current box. Compare the box art and the set number with your own listing.

Set numbers: where they help and where they trick you

A set number in a title is the strongest signal on a LEGO listing, and also the one sellers misuse. Three habits cause most wrong buys.

1. The right number on the wrong set. A seller types one number into the title while the photos and piece count show a different set. Check the number on the box in the photos, not only in the title.
2. Part numbers that look like set numbers. Other products use five-digit numbers too. A real set listing names LEGO and describes a building set.
3. Compatible or knockoff listings. Titles such as "compatible with 21348" point at a set number but sell a different brand. The brand field and the box in the photos settle it.

Partial sets and minifigure-only lots

These are the traps that cost sellers most. The set number is in the title, so a simple keyword search treats the listing as the full set.

• Bag-only listings. "Sealed bags #10 and #11" of a large set is two bags out of many, not the set. Words like bag, bags, partial, incomplete and "no minifigures" are the giveaways.
• Minifigure-only lots. A listing for the figures from a set, or a single figure, carries the set number but none of the bricks.
• Manual-only and box-only listings. Instruction booklets and empty boxes also use the set number in the title.
• Different set, similar name. A large collector edition of a vehicle and a smaller set of the same vehicle have different numbers and different prices. Always confirm the number against your own listing.

Piece counts are not lot sizes

LEGO titles often carry a piece count, such as "3778 pcs". A piece count describes how many bricks are in one set. It does not mean you are buying thousands of sets. A genuine lot, such as "lot of 2 sets" or a 2-pack, is a different item from your single set.

If a listing says two sets and your Amazon item is one set, it is a different item from yours. Count what the photos show.

Before you buy

Buying on eBay to sell on Amazon can add risk to your Amazon account. Items bought on eBay come with eBay order records, not retail invoices, and some sellers report that Amazon asked for invoices during an account review. Some brands and categories on Amazon also have their own rules. We cannot promise how Amazon will treat your account. Keep every receipt, read Amazon's current rules for your category, and start small. This is not legal advice.

New to the method? The step-by-step sourcing guide walks through it. The category MarginPing supports is power tools, and the same matching ideas apply there.

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