I might start selling off my collection of mission patches (and I don't mean the ones I designed, ones that are either official or designed by other fans. I'll gladly sell the ones of my design too, but I mean I'm pretty sure that ship has sailed)
like, from what I can see, a genuine Falcon Heavy demo patch is going for $80 USD on ebay. I have other miscellaneous patches that aren't as common as, say, space shuttle patches, like ones for Cassini, Chandra X-ray Observatory, Mars Odyssey, Mars Pathfinder, Mars Reconnaissance Orbiter, and a really cool NROL-22 patch I got from a former ULA employee (even though this mission predates ULA) that I can't find when googling it (never mind I found it, though it look like a different make... either I have one from the employee batch... or a cheap knockoff lmao)
I have a lot of others, but they're more common and relatively easier to find
like the problem is that the heart of my collection is stuff that has value to me, aka from missions I saw launch or that I care about. I have others of course, a handful being random stuff from the afforementioned ULA employee. it's also not just patches, he gave me launch coins and pins and stuff only given to the employees, but still. I doubt many people would care for some random delta iv mission carrying whatever military satellite