Brickeconomy: is it accurate at all?

[danth]

I hate to say it, but BrickEconomy values seem to be totally made up nonsense. Look at its estimate for a new Futuron Monorail 6990. It shows a value of like $3600. It also shows multiple "sales" around that price in 2023 in its graph. However the only places you will even see those sell new are bricklink and ebay. And bricklink has zero new Futuron Monorails sold in 2023. Ebay shows one new Futuron Monorail sold in the 2023, for $1600. Basically, nothing to justify the prices on BrickEconomy. BrickEconomy seems to base its values on asking prices, which mean less than nothing. 

Brick Economy: Futuron Monorail (notice multiple "sales" in 2023 in the graph)

Bricklink Price Guide (notice no sales of new Monorails in the last 6 months)

eBay sold items (notice only 1 sale of a new Monorail for only $1691)

Am I crazy or is BrickEconomy just using asking prices in its estimates, which are generally inflated nonsense, instead of using actual sale prices?

Edited June 23, 2023 by danth

[Mylenium]

That site is complete nonsense. Lots of fancy talk about AI and ML algorithms, but at the end of the day none of this has any meaning. Basics of statistics: Sample size is the main determinant for any form of extrapolation and where there's not enough samples, there can be no reliable prediction/ estimation. Or in other words: They're pulling pricing valuations out of their megablocks.

Mylenium

[danth]

Thanks @Mylenium for the feedback. Yeah the AI thing sounds like pure hype.

Are there other sites out there that have significantly more sealed vintage Lego sets sold than Bricklink or eBay? I feel like I would know if there were. If not, then the points on the BrickEconomy graphs are definitely based on asking prices.

[Mylenium]

I don't think you'll have much luck with that. Our German Brickmerge.de site would be an option to track retail prices for reasonably recent sets and extrapolate from there, but other than that I think this is one more case where gut feeling beats mathematics. Again it's the problem of sample size. Highly coveted expensive sets just don't sell en mass every day and you can't determine much from a few random sells, least of all with how different the markets in different regions are.

Mylenium

[Jorge S Pallas]

Reviving this because the problem danth identified hasn't gone away.

I'm a collector who got tired of manually refreshing eBay across multiple countries for 5 sets, so I ended up building something (https://scoutloot.com). Relevant to this thread because I took the opposite approach to BrickEconomy, instead of predicting what a set will be worth (which as Mylenium correctly pointed out requires sample sizes that don't exist for expensive vintage sets), I focus on what's actually selling right now across 12 eBay marketplaces + BrickOwl.

 

 The reference benchmark depends on what we're measuring. For the "X% below market" you see on deal cards, we use BrickLink's current stock price (specifically the 2nd cheapest listing, not the inflated average). For the Deal Quality Score that gates whether a notification is actually worth sending, we use BrickLink completed sales weighted by recency, plus our own recorded market data from eBay/BrickOwl over the past 7-90 days. Two different lenses: "is this cheaper than what's available right now?" and "is this genuinely a good deal based on what people have actually paid?"

On the regional pricing issue that's one of the things that frustrated me most. A "deal" on eBay.com is meaningless to a European buyer once you add shipping and duties. We calculate total landed cost per country, which sounds obvious but apparently most tools skip it.

 

 We do have an investment analysis feature (Crystal Ball) that scores sets on 11 signals, peer set appreciation, BrickLink supply trends, demand scores, price momentum, etc. but every signal is shown individually so you can see the reasoning and disagree with it. Transparent data > black-box predictions.

BrickLink Price Guide is still the gold standard for actual sale data on vintage sets. For current/retiring sets, automated scanning across marketplaces fills a different gap.