Those have no intrinsic value other than their metal content to anyone but a fellow collector. As with anything, a private sale will get you the most if you can advertise them (CL/trading post, etc) and afford to wait for a buyer.

Metals buyer or even a retailer/pawnshop will rape you below spot on the metal content, because they need some margin to move it. As metal, you're talking $2.55/lb as of today, less 5% or more for selling to a retailer.