Or at least that's what the eBay listing said. The top swatch is actually from a game-used stirrup. That's not the same as a sock but it's worn on the same part of the anatomy.
Like the 2004 Donruss Diamond Kings I posted a few days ago, this is another set which is full of inserts. There were 209 inserts with this set. There were 89 cards in the base set and 4,345 different insert cards. All of the insert cards had either an autograph, a relic, or both. Many cards have more than one relic, some have as many as 4. All were serial numbered.
I never saw a pack of these cards in the wild. According to Beckett, there were 2 inserts per pack, so I'm guessing the packs were expensive. They cards are not hard to find on eBay and some of them are reasonably priced. I paid $14.32 for this Schmidt card. I probably wouldn't spend so much for any other player.
In recent weeks I've managed to buy 6 cards from this set: J. D. Drew Prime Patches Major League Materials Triple Swatch (actually I got this a year ago, the card has a bat, a jersey and a shoe); Tony Gwynn Prime Patches Portraits Jumbo Swatch (this card has about the largest jersey patch I've ever seen, it's more than half the card); Jim Thome Prime Patches Portraits Team Logo Patch (bonus, he's a Phillie on this card); Moises Alou Prime Patches Portraits Triple Patch (bonus, he's an Astro on this card even though he left the Astros in 2001. It has 2 jersey pieces and a bat), Jeromy Burnitz Prime Patches Portraits Quad Swatch Prime (it has 4 jersey patches, 2 white, 1 black and one gray with a piece of patch on it). I paid less than $6 a piece for these (not counting the Schmidt). Not bad considering that two of them are surefire future Hall of Famers. You can see my whole collection of these here.