Sure you can bid from the US,i buy also hair from the US and i am from Belgium.
If you type 'human hair' on ebay and go worldwide (surch) you will find more than 30 pages.
I don't have paypall,so if i buy things on ebay i send cash money (well hidden) in an envelope.Never had any problems,and in some cases working that way goes even faster than with banktransfers!
If i need USD,i just go change my euro's for $ at the bank,as simple as that!