I've done donations of baskets of asst. cards for our church auction. I would coach them on pricing. Per other posters, I had baskets of asst. cards in baskets (25) and they priced at $25 (and got that). My cards all have lots of nice embellishments, layering, ribbon, brads, eyelets, etc . $25 for 25 nice cards=someone got a good deal!!
Coached them on subsequent auctions as to starting price so that they wouldn't undercut what they potentially could get!