Depends on the kind of tape. If its old tape, especially old Ampex from the 80's, then you're really just buying old spools. I've seen tape sold on auction sites that's probably 40+ years old, old Emitape, Scotch etc. Given the price you're looking at I'm guessing that the tape you're looking at is similar, but if its reasonable tape (Maxell 35-90B, Zonal etc, or (unlikely) Quantegy) then it might be a good buy.