If you want to make quick profit, you should start investing in powerhouse cases, the quantity is going lower by now and the price is going to spike even more if the amount keeps going lower. so this is the last chance you can get them for this low price if you're considering to unbox,As I'm trying to help everyone profit :D

Proof as they're not dropping anymore (from tf2 wiki) :
https://wiki.teamfortress.com/w/index.php?title=Mann_Co._Supply_Crate/Retired_series&redirect=no#The_Powerhouse_Weapons_Case