I do not see the problem here as your sale was not used for the range. If anything, that sale supports the drop here. In general, the overpay rule didnt make hats worth "more", i.e there was never any reverse overpay rule. You cant say "it sold for a hat priced at 90 so it should be 110 because it was overpay" [110 is an example figure here], because whatever figure you put there that's not 90 will be artificially made up. Its pretty much the same reason the overpay rule got removed, as the general rule of thumb of 10% overpay in unusuals (which used to be really common) became far too unreliable, and was mainly causing hats to gradually drop at some point. Its near impossible to determine how much overpay someone wants in what kind of hats.

Sure, if your purchase was far lower than the other sales on this hat, then it will be excluded, and then it means you got "overpay" by your definition. Thats why we always check how sales compare to others. Your trade was likely still a good one, as even at equal bp prices, Id expect a burning slug to be easier to sell than a fb hazmatten.

On a side note: it seems like you sold yours by now for what seems to be 85 keys. I was going to say I'd prefer to see more sales here (as 92 pure went pretty fast for a hat this tier), but if you sold it for around that amount, then that'd support this value rather than disprove of it. Could you confirm your sale or provide the correct sale if it was wrong?