If it does not have paperwork of authenticity plus warranty, you are going to get in trouble down the line no matter what you do.
My advice is order them for yourself, sell a few at the flea market or local papers, and go from there.
If they are really popular than order a full wholesale batch, list them on uBid and eBay but indicate that they are 'Designer inspired' Jeans since you don't have the paperwork.