It might feel as if some Lego sets are much worse value than others. But some dedicated numbercrunchers suggest the price per brick is largely stable across both sets and time.

(Before the numbers, two rants as a Brit of a certain age. It’s Lego bricks, not Legos. And the only true Lego set is one full of generic pieces with which you build your own design rather than follow a pre-made template.)

Ken Steif, who runs a city planning data science company, took a break from the day job to apply his skills to Lego prices. He used data from Brickset, a site that catalogs Lego sets and values for collectors. As shown above, Steif found that once you take away premiums for licensed sets such as Star Wars, there’s a fairly decent relationship between the number of pieces and the price of a set. Overall, each additional piece makes the set nine cents more expensive.

The calculations follow a similar piece of research back in 2013 that found if you adjust for inflation, the per-piece price of Lego had been relatively stable for around a decade at around 10 to 12 cents per piece. The difference between the two calculations may be that the latter looks at the overall cost per piece while the former looks at the cost of each additional piece. With a small, basic set, more of the cost is eaten up by factors other than the bricks themselves.

There’s also an interesting Reddit debate on the figures in which one former Lego employee notes that sets which seem unreasonably expensive often contain rarer pieces that aren’t used across the range, while others note Lego has reduced the number of colors it uses for the most common pieces as a cost-saving measure.