I can't speak to the value of the whole system, but the Pentium III-S 1.4Ghz is the fastest Socket 370 CPU out there.

I'd personally sell the case + PSU, motherboard, CPU, CPU cooler, RAM, drives, and expansion cards all separately. You are more likely to sell everything separately than all together. Just make sure everything is clean and updated (BIOS, firmware, etc.).

Also cant comment on value but can say you will definitely get more by splitting it!

Thanks for the replies and advice . I just might part it out and keep the case, which must weigh thirty pounds!

The case looks very reminiscent to the Chieftech Dragon, though yours is made by Antec. It's probably build roughly the same time and I can imagine it will be very heavy!
The insides also look very similar to that Chieftech case.

The system itself looks as if it was build by a retro computer hobbyist. It looks well build, except for it not having an exhaust case fan.

I'd agree with it being easier to sell the parts separately, though if I were you, I would consider keeping it as it hardly gets any better than this.

Nice case.
I have one too.
Antec SX835II

If you already don't have a similar system and you have a space for storage, keep it. It might not interest you now, but in a few years you could regret it...

Thanks everyone for the suggestions. I'm going to hang on to it since I don't have a financial need to sell it, and figure maybe I can put it to good use 😀

By the way, If I were you, I would have a look at that PSU's capacitors, just to be safe .