LEGO Prime Days: −38.5% displayed, −13.7% real — how to read a struck-through price

A struck-through price always has a reference

• List price: set by LEGO, it's almost always the one struck through.
• Best price elsewhere: what other sellers ask at the same moment.
• Price paid: the one that counts, shipping and conditions included.

A discount vs list price tells you what LEGO would have asked on its own site. A discount vs the best price elsewhere tells you what you really gain by buying now, here, rather than at a competitor. They're two different pieces of information, and only the second helps you decide.

Ten "all-time best prices", recalculated

The median displayed discount is −38.5%. The median real discount, against the best price already available elsewhere the same day, is −13.7%. Almost three times smaller. The real gap ranges from −5.0% (21596 Minecraft) to −24.1% (75444 AT-RT). In other words: for these ten sets, other sellers were already under list price, sometimes very close to the "all-time best price".

Three reflexes during Prime Days

• Compare to the day's best price, not the struck-through one. That's what inflates the percentage.
• Record the price you actually pay, shipping and conditions included. It's the starting point of your ROI.
• If you might resell one day, also check the market price: what the market pays today for this set, new.

My take

A −14% deal is still good news if you want the set. The problem isn't the discount, it's the number you remember. Whoever keeps "−45%" in mind will feel they got an exceptional deal and compute their ROI on a false basis. Whoever records "€21.90 paid, €28.49 elsewhere the same day" knows exactly where they stand. Less exciting, far more useful.