Way back in 1997, Jeff Carter was this fellow that put up "Jeff Carter's Lola Bunny Page" that was mostly GIFs and one-by-one displays of Lola Bunny merch. He had amassed quite a bit, and much of it was for sale. The site rarely updated, though, and was pretty much stagnant by 2000 or so. It's gone now, so I can only speculate why.
1) He sold all or most of his wares, so the site wasn't needed any more. He may have moved on to other venues, such as My Little Pony, but he's keeping his name off of them. I never got the impression he was a collector per se, more like a retailer, bagging the early wares cheaply, then reselling them at significant markup. The nostalgia market never seems to run out of money.
2) He's still got a goodly stash, but sells only duplicates, leaving a museum of memorabilia in effect. Rather than deal with the many excited weirdos online, Jeff keeps his "toys" by invite only, likely using a frontman to vet those that declare interest. I haven't heard about anyone taking Space Jam swag on tour, like on Antiques Roadshow.
3) Jeff and his wife got older, raised kids, and outgrew their Space Jam days. Priorities change, y'know?