Which is where things get complicated. With that long a history, some of the volumes are naturally much harder to find than others. The original twelve-volume run from Bantam can usually be found via ABE.books or ebay at reasonable prices, but the three volume "Card Shark" series that followed, published by Baen Books, is considerably more challenging, especially the third and concluding volume of the triad, BLACK TRUMP. If you do find it, it will likely cost you a lot more than it originally sold for.
That being said, even BLACK TRUMP is easy to find compared to the two hardcover originals published by iBooks when they brought the series back after a seven-year hiatus -- DEUCES DOWN, a typical Wild Cards book with stories by various hands, and DEATH DRAWS FIVE, John Jos. Miller's solo WC novel. DD5 was published only one week before iBooks went bankrupt and closed up shop. As result, to the best of our knowledge, only 600 or so copies ever got into the bookstores. (Was that the total print run, or are there more sitting somewhere in a warehouse? No one seems to know, and there's no one left at iBooks to ask). In the years since, and especially after Tor and INSIDE STRAIGHT kicked off the second coming, demand for the book has steadily risen, along with its price. It has become the Holy Grail of Wild Cards collectors.
He's not kidding with Death Draws Five. If you can find a copy under $80 right now, you've found a good deal. It's the only book in the series I don't own.
I got lucky with the paperbacks and, no lie, found almost the complete set in one glorious trip to Uncle Hugo's - including all three volumes of the Card Sharks trilogy. Didn't realize those were on the rare side. I later received Deuces Down as a gift. Which leaves Death Draws Five. Every time I check in at Uncle Hugo's, I am prepared to lose bladder control should I see a copy on the shelf. I am prepared to snatch that copy, clutch it close, and call it "my precious". That copy just hasn't shown up yet.
I knew that there was an e-book of Death Draws Five available, but I've only read through the first seven books (plus 18-20), so just reading it isn't a priority at the moment. My library also has one precious copy, if it came to that. I just want a full collection in print editions.