Re. trading – your point is no different from a thread on, say, the effect of (modern, i.e. non-retro) game trade-ins. So what’s ‘Retro’ got to do with it?
Insofar as ‘Retro’ is concerned, the effect is absolutely inconsequential, since the lines are just not carried by retail anymore (unless in some obscure Latin American country) – ergo wholesalers haven’t been purchasing any new stock from manufacturers or publishers for aeons – ergo manufacturers or publishers just haven’t been manufacturing the consoles/carts/games for aeons. So, sorry but I just don’t see where you’re coming from?