I compared retail vs secondary market prices for ~4,000 retired sets. Some interesting patterns.

Analyzing nearly 4,000 retired LEGO sets, the data reveals that the common belief of LEGO sets returning an 11% annual profit doesn't hold true. The average appreciation is +27.9%, but the median is only +0.3%, indicating that most retired sets barely break even. The study examined the original retail prices and current trading values of 3,973 retired sets.

The study found that the theme of a set is the most significant factor in determining its value. Bionicle sets have an average appreciation of +310%, Architecture +98%, and Star Wars +30%. In contrast, Jurassic World sets have depreciated by -10%. Discontinued themes like Bionicle, Mixels, and Power Functions perform well because their supply is permanently limited. Sets from Disney Wish and Dimensions Starter Packs have lost significant value. The data also shows that the median set doesn't break even until five years after retirement, with the most significant appreciation occurring between seven and ten years. Sets from 2015-2016 currently have a median appreciation of +50-60%, while sets from 2020 are at the breakeven point. Sets from 2021 onward are still underwater.

The research also found that cheaper sets tend to perform better than more expensive ones. Sets under €20 have a +10% median return, while sets over €350 lose money on average. Surprisingly, sets without minifigures appreciate more (+8.2%) than those with them (+0.1%). However, individual minifigures can be extremely valuable, sometimes worth more than the sealed set they came from. For example, a Ninjago accessory set with a retail price of €61 has minifigures now worth €302. The author's recent purchases, the TIE Interceptor and Cantina, fall into the Star Wars theme, which has a +30% median appreciation.

For LEGO enthusiasts looking to invest, this data provides valuable insights. Consider focusing on sets from discontinued themes or those with a lower initial price point. If you're a collector, you might want to consider the value of individual minifigures. If you're looking to display your sets, consider a LEGO display case to protect your investment.