That second sale shouldn't be used as proof. On a trade involving 4 hats, especially hats with old prices, there is just way too much uncertainty. You are implying you can accurately price 3 hats to set the price on this. The value there is 2.3 +/- 1 buds. I wouldn't be opposed to 2.5 flat and using the other sale to indicate that the general value here is close.