There's been a couple of very good points made. But value doesn't necessarily mean dropping a big wad of cash on a recording -- jog up to the post by Bunnyears above about the $2 CD.
I know that certain recordings are worth a lot to me moneywise but they even have more personal value and perhaps even sentimental value. For example, I don't know how high I would go on a really nice original issue vinyl pressing of Frank Sinatra's - Where Are You?, but I can tell you that I have spent upwards of $25 to $30 for worn out and scratched up examples (of course the sellers represented them as near mint!). I thought the Sinatra album
Songs for Swingin' Lovers was getting pretty rare for an original 1950s pressing, but I managed to find an exceptionally nice copy for $10.
And I won't be hestitant to admit that I have been taken a few times. I bought about 60 original 1950s RCA Victor classical music albums, paid about $3 each (waaayyy over my bulk lot price limit of about 75 cents per record. The seller talked them up and I was caught so easily that it took a pair of needle nose pliers to get the hook out of my mouth.
Out of that batch of records, I doubt that more than 5 were keepers. The rest of them were junk. Very nice jackets, but the records were completely worn out. I was plenty pissed at the seller, and at allowing myself to get sucked in so easily.
It seems odd to me that I would consider chasing after a 1/4" Stereo tape of Kind of Blue for over $250, but probably would not consider dropping a lot of money on any single classical, rock, or blues album (boxed sets are different). I didn't think twice about ordering the John Coltrane complete Atlantic recordings on 180g vinyl or The Doors boxed set on 180g vinyl from Rhino (both were about $200).
But truth be told, I have found just as much joy and pleasure in the following record:
This particular record cost me all of 50 cents as part of large lot of 100 albums that I bought for $50, and I doubt that this album had ever seen a turntable. It sounded glorious, and I looked at my wife grinning as the record played, calling it "burried treasure." I wondered how long that record sat in a box before it found its way to my listening room. I think the contrasts can be rather striking.
BTW, I bid on and won that copy of Kind of Blue on 1/4" 4-track stereo tape. So I just shattered my old high of $70. But the more I thought about it the more I persuaded myself that you only go around once and I wasn't too sure that another opportunity would present itself anytime soon.
--Jerome