well what they are going for on ebay is what people are paying, and thats what makes the valuable. Although, not to necessarily contradict myself, ebay prices tend to sometimes be over-inflated, or under-inflated, you just have to know what it is. An appraiser if you think they are worth that much. ** My great uncle left my dad a bunch of what appeared to be junk. A lot of old boxes and stuff from when he ran an antique store. Well after digging around, we found 2 or 3 tubes of uncut baseball cards. The uncut roll was probably 5 foot long. We had them appraised, or an honest opinion from an aquientence and it was a pretty good amount if i recall correctly, a few hundred bucks.**
edit: forgot to add my appraiser story.