Warfer, definitely pick up a deck and have a hoot going through all your old tunes!! I picked up an old Luxman deck for $50.00 off e-bay that originally retailed for $800.00. The thing works perfect. But beware - it is a crap shoot. The head could be shot, belts stretched, pinch roller shrunk & dried up, and so on. I guess I got lucky. I'd try a pawn shop where you could "demo" it first.
As far as sound quality goes........well, if you can get past the hiss, flutter, drop outs, and all the other anomalies you aren't used to hearing, you should do fine. Just enjoy what is on them! There will be a few lost gems you will certainly find, and those make it all worth while.
BrotherBob made a very valid point. If you do find something that is rare and out of print, try to copy it first listen through. Since my deck was a single, a tape-to-tape copy was impossible. So, I ran the output from the tape deck to the sound card input on my computer. Ripped it to the hard drive, ran it through some filters, and burned it to CD. I can't recall what software I used to edit the songs before burning (it was 7yrs ago), but I remember being happy with the improvements at the time.
Shawn