how the forget does trading economy work
It works with refined metal. Or reclaimed and scrap metal, of course, but refined metal's the base.
I'll make an educated guess and say that people tell you "wtf man this item is way more expensive than your two weapons/single scrap/single reclaimed" or you see people around selling weapons for a scrap and get confused when you try do to that yourself because people say "this is worth half a scrap mate".
backpack.tf and its community have found (and keep finding) the price where things are most commonly sold successfully and for the most part you will find the price of an item there. "1 ref" is one refined metal, so "0.33 ref" is one reclaimed metal and "0.11 ref" is one scrap metal.
This post is kinda messy but I hope it's understandable enough. And also, be sure to have steam mobile auth because otherwise you will have to wait a week or two to get anything from trading.