Couple things here:

Firstly, a small thing, but you should shorten the days of the compares to as close as possible to the actual sale, like this:

https://backpack.tf/profiles/76561198255610068#!/compare/1551744000/1552262400

https://backpack.tf/profiles/76561198300359095#!/compare/1551744000/1551830400

Secondly, while I applaud you going out of your way to find the sales, the only sales that are considered valid are ones that are three months older than the current day the suggestion is posted (so that would be Dec 17 & on are valid). So your second and third sale can be thrown out immediately.

The third thing is that the bread bite was added on, which you dont seem to mention. A small thing, and it doesn't change the price (not by much, anyway)

The final thing is that I ='m not certain that the trade is all accurate; the items move too fast from the Sellers inventory, so I can't tell if the hat DID sell for what you say it did. If you could ask one of the people involved in the trade for a screenshot of their trade history, that would lend a lot of credit to your suggestion.

As is, this suggestion is o, if lacking proper evidence. if you can get some more solid evidence, then you would be golden.