My cool vacu-formed white plastic Mego bridge set, from "Star Trek: The Motion Picture", was bought on eBay about 1999 or 2000. They were quite rare, and I'd always coveted them.
I plan to paint it eventually. It's populated with my Mego TMP action figures and customised alien ambassadors. Several of these were also eBay purchases. I love the way it looks like the ambassadors have just walked out of the framed lobbycard.
To think I once wrote to Heroes World and had the chance to buy the aliens at these prices, but didn't complete the order: