This is one of the first Ultraverse items I collected after a long “career” of chasing down Valiant stuff. Like the certificate says, it’s a printer’s proof. I suppose that means this was taken from some of the first comics off the press, and the sides have not been trimmed (it looks sort of like a newspaper’s edges). It’s definitely different, and fun variants like this are part of why I like collecting this stuff.
Prime was the inaugural launch title from the Ultraverse, and this is one of the ways Malibu commemorated it. As far as print runs … who knows? Printer proofs are created so editors can check for mistakes and color corrections, so normally the print run should be small. I don’t recall seeing any of these back in the 1990s and I have no idea how they were distributed.
I paid a couple of bucks for mine. Every now and then — a couple or three times a year — they show up on eBay. Sometimes there is a minor bidding war to help the price reach double figures but usually these sell for a couple of bucks.