You would probably have better luck selling them if she wore them and then you could hit up websites like ebanned or naughty bids. I am sure that there are guys out there with bra fetishes. I just sold a couple pairs of my shoes to a guy that contacted me about having a foot fetish. He sent me $100 for three pairs of my used tennis shoes. If someone is willing to buy my used and stinky shoes then I don't see why someone wouldn't want to buy your wifes bras. But yeah, she needs to wear them first and I would also suggest that you take a picture of her wearing them so that you could post it to the site that your selling them on.
Anyway, it's up to you but I am just trying to help you out with the sale.
