Maybe someone local will take them if they got a total shop job pin or unfinished cabinet and want it original"ish" come their way. Other than that, probably just as easy to get cheap replacements

I did a parts trade with a guy who decided he wanted to go back to WPC back box speakers from aftermarket kits.
Apparently the amplifier in STTNG doesn't work well with aftermarket speakers (?). I think it's something to do with the amp's power output (?).
Anyways he really wanted to go back on his STTNG.

I personally like aftermarket speakers myself.

Other than that one instance nobody seems to want them.
There are websites that have ideas for repurposing them, but removing the magnets seems a bit much unless you are handy with power tools.
Magnetic tool holders seemed like a good use.

I sadly ended up taking them to our special e-waste facility so they at least wouldn't pollute the environment as much

Yep. People who restore games or build their own test rigs could make use of them for a fair price.

I think I had $4 on a speaker set on my table at Allentown and no takers...

What may have happened is he had aftermarket speakers that had low sensitivity: many car audio speakers do. In that case, they would be much quieter at the same amp level as the stock speakers. That might explain why he'd want to go back to stock.

Aftermarket speakers work great, if you know what to choose and also how to hook them up.

As far as STNG, no problem with upgrading the speakers. In fact, WPC DCS is one of the better sound systems for handling aftermarket speaker systems. I had a STNG, and swapped out all the speakers. It sounded much better than the stock ones.

Just store them, just wait...... someday, somehow, you’ll need one

They do not have much monetary value but I do use them for testing or to replace a blown one every once in a while. I used a couple of them to replace arcade game speakers.

No, I do not need any more. I have about 6 of them just collecting dust.