Buying used sets safely
Secondhand sets are one of the best deals in the hobby — retired models, bulk parts lots, and childhood collections all change hands every day. But used buying has its own skill set: checking that everything's there, judging condition, and knowing what to walk away from. Here's how to buy used with confidence.
Where used sets come from
General secondhand marketplaces, local auction sites, garage and estate sales, thrift stores, and fan conventions are all common sources. Each has a different trade-off. Online listings give you the widest selection but you can't inspect anything in person. In-person sales let you look the lot over, but selection is luck of the day. No single source is "the" place — most regular buyers use several, and the best deals usually go to whoever checks most often, not whoever looks hardest in one place.
Before you buy: check completeness
A used set is only a deal if it's actually complete — or priced as if it isn't. Before committing:
Ask for a parts count or inventory. Serious sellers will have counted or at least bagged by step. Vague descriptions like "looks complete" are a yellow flag, not a guarantee.
Check the instructions. Missing instruction booklets can usually be replaced through fan-archived scans, but factor that in. A set with no instructions and no parts list is much harder to verify.
Know which parts matter. Common bricks are easily replaced from your collection; rare printed pieces, minifigures, and unique molds are not. When inspecting, prioritize the parts that are hard to replace. Ask specifically about minifigures — they're frequently separated and sold on their own.
Agree on the definition of "complete." Does it include stickers? Spare parts? The box? Get this settled before money changes hands, not after.
Inspecting condition
Bricks are durable, but they do age. Look for:
Sun fading and yellowing. White and light-colored parts stored in sunlight can discolor unevenly. A little fading on common parts is cosmetic; heavy yellowing on a display piece is a different story.
Chewed or cracked parts. Teeth marks on bricks (usually from childhood) and stress cracks around clips and hinges are common in well-loved sets. Decide your tolerance in advance — builders sorting parts for a collection care less than collectors rebuilding a display model.
Off-brand lookalikes. Mixed lots sometimes contain compatible-but-not-genuine pieces. Check the studs: genuine bricks carry the brand marking on each stud. A few mixed pieces are normal in bulk lots; a set advertised as pure that isn't is a problem.
Smoke and pet odor. Hard to judge from photos, but worth asking about. Odor usually washes out with cleaning, though it takes effort.
Cleaning used bricks properly
A good wash makes a used lot feel brand new. The safe method: warm (not hot) water with a small amount of mild dish soap, a gentle agitation, then thorough rinsing. A mesh laundry bag keeps small parts together in the sink. For stubborn grime, a soft toothbrush does the work — avoid anything abrasive.
Dry completely before storage: spread parts on towels, and let them air-dry a full day. Trapped moisture in a sealed bin leads to musty smells. Never use a dishwasher or washing machine — the heat can warp parts — and keep printed pieces and stickers out of any soak, since water and scrubbing damage prints.
What to watch for in the deal itself
Photos that hide. If every photo is taken from the same angle, or the minifigures are "shown separately," assume the listing is telling a curated story. Ask for the missing angles.
Too-good lots. Large unsorted lots are priced by weight of uncertainty. They're great for parting out into a collection and terrible if you wanted one specific complete set. Match the lot type to your goal.
Payment and pickup terms. On local sales, meet in a public place and inspect before paying. Online, prefer platforms with buyer protection over direct transfers to strangers.
Your time has a cost. Sorting, washing, and inventorying a big unsorted lot is real work — enjoyable work for many of us, but work. A lot that needs six hours of processing isn't the same price as a clean, inventoried set, even if the parts are identical.
The bottom line
Used buying rewards patience and inspection. Ask the completeness questions, check the hard-to-replace parts first, wash what you bring home, and price the deal against the work it needs. Do that consistently and secondhand becomes the most cost-effective way to grow both your collection and your building skills — every used lot is also a surprise parts pack that teaches you new pieces.