how hard are they to make? and just how original are they? first you have to add in all materials, then the work it takes to matte, glass and frame the work. if it's limited addition, you can jack the price up as long as it's signed and dated. $10 sounds way to low. new baseball cards are sold for more than that. what i would probably first do is, bring the print to a framer and ask how much it would cost to frame it up. so that's your starting point on how much you charge.
---Mike Savad