This idea comes from me as a collector; I hate it when people don't read the notes and add me with an item that doesn't have the level I want, It gets really annoying ya know? And I bet it's also really hard for people to find collectors like me using trading sites. There Should be a way to show what level you want in the "Items wanted section", like with the craft hats or offers "Item". One that give the option of selecting the level you want in an item.
This could also be useful for craft # collectors as well.
It's just an idea i had( if this is added it's my idea and I want compensation XD jk jk but a polite thank you and a WOW why didn't we realize the useful of this before would be nice.)