Office Max and Staples often have them around the start of school time. My guess is that they probably have some left over but I can't guess at the cost. My Office Max had a leather'ish case for them this week on clearance for $3.00. You will want some sort of case for them to keep the face from scratching when not in use.
Don't know what part of MA you're in, but it was the Marlborough store that had the clearance cases.
Good luck..