Hello gotrich,
I agree with what's already been said, but there might be some numbers among them that are not generally available eleswhere.
That's the only possible reason to buy tapes. I wouldn't give more than a couple of bucks for ones you might want.
I recently discovered a tape of "Louis Jordan with a number of songs not usually found, it was worth the time downloading the words and and running them on KHPro.
Again I can't stress enough
www.audiotoolsdirect.com as a source for finding programmes for converting old music sources to PC.
Regards from across the pond.
Garry