if you haven't already, you should read this: https://forums.backpack.tf/topic/6033-rules-for-unusual-price-suggestions/

you may keep it open for more feedback if you like, but in my opinion the suggestion is invalid, so i would close it until you can either get someone to help you with it, or you go over your evidence a bit more and the rules to try to form a more accurate suggestion. i can't say how exactly you would suggest this because i'm honestly not good with pure + unusual sales, but the best of luck to you.

You will need to close this. You cannot have a range from one sale nor can you have a decimal price for something this expensive.

There are a few other sales on your item's history that'll need to be looked into as well.