Keep dated, condition-matched estimates separate from purchase costs, asking prices and completed sales.
1. Decide what the number is meant to represent
A replacement estimate, a current asking price and a likely sale amount answer different questions. Before adding up a collection, decide which one you are recording. Do not combine those measures in a single total and then label it as expected cash.
Keep acquisition cost separately. A bargain purchase can cost less than a current guide estimate, while an expensive purchase can cost more. Neither situation makes the purchase price a reliable substitute for a current condition-matched estimate.
2. Match the item and condition before the price
Use the exact set or catalogue item and the relevant condition. Separate New and Used copies and describe whether figures, instructions, boxes or other expected items are present. If two physical copies differ, value them as separate copies rather than multiplying the best example by the quantity.
For loose pieces, confirm the item, colour and available quantity. Watch for pieces reserved for assembled sets or active builds: counting them both as loose stock and inside the set can inflate the overall picture. Decide how those categories are represented before combining totals.
3. Read sales evidence differently from listings
BrickLink’s Price Guide distinguishes past six-month sales from currently available items. A live asking price is a seller’s offer; it is not evidence of a completed transaction at that amount. Check which view and condition you are using before recording a figure.
The quality of a comparison matters as much as the number. Similar names, different editions, incomplete figures or another currency can make an apparently precise comparison unsuitable. If a guide has little relevant evidence, keep that limitation with the estimate rather than treating a sparse sample as certainty.
4. Keep the source, currency and observation date
Record where an estimate came from, the currency and the date it was observed. A price without those details becomes difficult to interpret later, particularly when you compare an older purchase with a newer guide or review stock priced in several currencies.
Use a consistent reporting currency when assessing the collection. If you convert a figure, record the conversion assumption separately instead of hiding it inside the original guide price. An old estimate can remain useful as history without being presented as the current market.
5. Treat unpriced stock as unknown, not worthless
A total that excludes unpriced items is incomplete, even if the displayed sum is calculated correctly. Keep an unpriced filter and a count of items still needing review so the coverage of the estimate remains visible.
Prioritise the records that could materially change the picture: expensive sets, distinctive figures, uncertain quantities and items whose condition does not match the chosen guide. You do not need to refresh every common part before addressing a clearly misidentified set.
- Exact catalogue identity and condition.
- Completeness and per-copy differences.
- Source, currency and observation date.
- Unpriced items and possible double counting.
6. Record the sale result separately
When an item sells, record the actual sale amount and any known fees, shipping and acquisition cost. That result is different from the estimate you used while holding the item. Keeping both helps you understand which assumptions were useful and which were too optimistic.
Bricks & Giggles provides condition-aware collection views, unpriced filters, value history and sales records. Use those views together: estimates support a decision, while the completed transaction tells you what happened. No recognition result or guide price guarantees a future selling price.
Sources & further reading
Check the provider’s current guidance when identifying or comparing catalogue items.