Its a bit unusual for a young guy like me getting interested in the portable stereo environment, not invested into all of the online streaming stuff, and I dont even have a smartphone (however having calls and texts will be necessary in the future so it would be nice if i had a dumbphone with me). I like the usual boomboxes, walkmans, and everything in-between, yet im leaning more towards the Portable CD player environment, there is just one big problem though, and that there isn't really any kind of garage/carboot sales or any 'true' thrift stores around me, aside from a few cash-converters which, aside from random cd's which might have the tunes that i have slight interest in, do not fit my needs, so online is really the only place where it really suits my taste, and you can imagine that most items there cost a lot...
Have you looked at: Discogs Music Boomerang r/Cd_collectors Or the Facebook group "Cassettes, Vinyl and CDs. Buy, Sell and Trade Worldwide"
Welcome to the forum! Sometimes the hunt is difficult but I've found stuff in out of the way thrift stores and garage sales. Your also close to Japan, yahoo.jp Auctions have a ton of stuff, shipping might be more reasonable for you. We do have some members down there and it seems like you guys got a lot of equipment from the glory days. Unfortunately shipping is a killer nowadays, while I don't have a lot of portable CD players I have at least one big box of cast-off Walkmans, one day I'll start parting ways with them.
welcome mate ! a hobby means maximal input of time and money with minimal output. thereās loads and loads of people out there, who allready found out but still carry on. cheers to down under