I sell my candy bar wrappers by the each unit with the foil included for $4.95 and they go very well at that price on my website. As Bobbi said it depends on where you live, and what the venue is. I do better at a Christmas Bazaar than at a Flea Market.
Ink is expensive for color intense ones and people know this and I explain that when they question my price. I say that I don't charge for my time and designing services, but I do charge for the ink, paper, and foil They seem to accept that because they buy.
Should you want to know about specific products to price just let us know and we will see what we can do. Maybe others will offer you some suggestions.