if this actually happens, then this hat will be the first unusual hat to be worth less than 7 keys

Given the situation I do not believe that 6.5 flat is a logical conclusion. You're using but one out of 3 sales, even though the other 2 sales are much more in line with one another; sales-wise 6.5 is definitely the outlier.

6.5 happened directly after the unboxening and would normally be below buyers. Given the situation I agree a raise is not called for either, and I agree that making this 8 would be too high, but I dont see any other indications that 6.5 is a better value than current based on these data points and sellers (even after the crash). In this case, leaving this outdated is probably the best offer, but whatever the solution, 6.5 flat should not be considered here.

You'll need more solid evidence to get a hat priced this low.