I'm sure you could find a retro enthusiast interested in most/all of it depending on where you're located. I had some stuff I was clearing out when I was paring down my collection that wasn't even all that interesting and I had a couple people come grab all of it within a couple days. I did live in a big suburb of a major city though.

As for what's worth it to keep - definitely the floppy disks, especially the 5.25" ones. 3.5" are still reasonably available and affordable, but the 5.25" ones are getting harder to find. Especially since it looks like they may be Double Density which are very desirable for very old computers since later era high density floppies don't work very well with them.

RAM is a little more questionable since even stuff like PC66/100 SDRAM is still pretty readily available and cheap. Obviously it won't always be but I understand the tradeoff of time vs. effort to try to sell that kind of stuff if you can't find someone to take it all off your hands. If there's older stuff, or anything proprietary to specific machines like specific laptops that's probably worth investigating. Those can range from not worth much to Holy Grail level depending on the desirability of the machine and memory.

Random motherboards are a crapshoot too. There's been a big upswing in interest in the slot era P2/3 machines but there were some boards better thought of than others (VIA chipsets. Ugh.) and it was getting into the Capacitor Plague era. Might be worth investigating them to see if they're worth the trouble or not, if you end up tackling things yourself. That ASUS one in the pic might be interesting because it supports late-era P4s including the 64-bit ones that can be fun to do dumb things like run Windows 10/11 on it. The second one is a VIA chipset ECS board that I personally wouldn't want to spend a lot of time with even with the interesting dual socket/slot situation.

Hard drives are also kind of a crapshoot, especially if they haven't been stored well. They're prone to failure, especially if not stored well, and these days a lot of enthusiasts are accepting the loss of authenticity to use various adapters and mods to allow the use of CF cards, SATA drives, ssds, etc since basically every spinny HD is a ticking time bomb. If they're particularly interesting somehow, maybe older MFM/RLL drives and you can test them somehow they'd probably be worth it. Random 20GB IDE drive probably less so.

Optical and floppy drives are in sort of the same boat, especially if they weren't stored well like it looks like those weren't. They have moving parts and sensitive lasers/heads that don't respond well to dirt and humidity. That said the floppy drives are probably worth trying to clean up and test. SATA optical drives I wouldn't even bother with, they're still cheap and readily available (and still made), unless they're something particularly interesting. Maybe a Blu Ray burner or something. IDE ones are more questionable, especially if they haven't been stored well. If you have a convenient test rig to test them (both being detected and reading a disc) then maybe give them a go and see. Even fancy IDE CD-ROM drives and burners are going for $10-20 shipped on eBay and they're thick on the ground, so that's up to you. Not like you'd be throwing away rare treasure or anything most likely.

Ironically, despite being the worst to ship, any beige cases might be worth something if they're in remotely decent shape. They're reasonably popular both for retro builds and modern sleeper builds and originals are getting harder to find. Original PSUs in them are going to be hit and miss too, lots of good and crap ones back then. By and large if they still work today they'll probably be fine, but worth testing the voltages to make sure they make sense.

Anyway, I tried to keep this realistic. You'll probably get a lot of "KEEP IT ALL!" responses but as someone who has hoarding tendencies and has pared down his collection a lot to something more reasonable, I understand that sometimes you can't save everything and when eBay is full of whatever the thing is for $5 shipped you can't spend months trying to sell a box of them on top of the annoyance of selling things online. Plus I knew anything I gave away had a 50/50 shot of ending up in someone else's hoard pile so it wasn't even like I was necessarily passing anything on to someone who might use it.