You may be waiting a long time there. A bubble may burst, and I am not sure I would count this as a bubble, but it is probably never going to be like the 80s and 90s again, times where people generally just wanted their silly old toys out of their garage/attic as their kids were onto the new shiny (or maybe even passed them by like a pogo stick) and would sell it to you for pocket change. Beyond that as the populations of gamers grow and the supplies of games remain the same, or even slightly dwindle as such things are hardly indestructible, then it only takes a small fraction to want to "see where they came from" (which of course will continue to be promoted) or a few others to want to relieve their past to generate demand that strips supply. Beyond that even with the inflated prices it is still cheaper than playing with vehicles and other such hobbies in many cases.
I am still of the fuck repros opinion, even if they cleaned up their act a bit it is still direct, straight up, paid for piracy and for my money no different to selling a CD with ROMs on. What I more wanted to question was the designer clothes thing -- I do not have a high opinion of the materials usage and design quality of most fashion types (fashion is one of the world's oldest cons and all that) but they do occasionally operate above the baseline and make something of marginal interest, to that end having more sensibly priced versions of those can have some practical appeal.
On collectors then yeah right now it is easy enough, at least if I can see the PCB and have a reference, I reckon though I can make fakes that you will need a proper lab to test for, and we are probably not too far off having it profitable -- some of the higher feature size Chinese chip fabs are rapidly coming down in price for fairly modest runs, you find some donor boards or spend a bit longer also colour matching a PCB and you are done (give or take faking a silkscreen and maybe a laser etching). Depending upon the people doing it then the better test will be probably be checking their history as few will likely have properly aged and sufficiently used ebay accounts to sell things on, or may well have to pretend they are a lucky bastard and found a box of goodness from their dead uncle's old game store in the attic.