Good question. In my heart, one card would not be worth my collection at all.
However, back in 1989, I was able to track down a 1954 Stahl-Meyer Franks Mickey Mantle that had been in a SPORTS COLLECTORS DIGEST Mr. Mint Alan Rosen phone auction. I won't give you "the full load of hay" so to speak, since my story does not explicitly answer the OP's question of ALL for ONE.
You see, the card did not sell in the auction, because Mr. Mint was blown away by the card's appearance, and listed it in SCD as MINT, but he failed to notice the faint front crease. The consignor must not have mentioned it. Back the card went to the owner, a very well-known figure in the hobby, who only dealt with the choicest of items.
The owner gave me 2 months to raise the money----$2,500, a LOT of money for one card at that time. In 1989, one could place a large ad in SCD and get great results, IF they had the right kind of stuff for sale. With God's help, I just made it.
The owner was true to his word, and saved the card back for me. When I got the card, it was precisely as he described it: a faint, but definite, half-inch "front crease" starting at the middle left front side of the card, but not touching Mickey at all. Otherwise, that Stahl-Meyer Franks Mantle was GEM MINT and dead-centered! For a 1954, that's saying something significant, because Milprint Printers changed the way the cards were cut in 1954-55, creating sheets of all 12 cards separated only by die-cut tabs. The cards had much more rounded corners, which meant that unless the card was printed virtually centered, it would look off or even slightly mis-cut.
Sorry guys, I'm getting verbose, again.
Long to short, I turned many cards and items into 1 card, and have NEVER regretted it. So, no, I wouldn't give them all up for one, but I gave up a bunch of nice items for 1 great Mickey Mantle.
If you've read this far, thanks for listening.
Cheers. ---Brian Powell