I think the keyword here is "I picked up a P3 *COMPUTER* (Everything except hard drive) for $25". Obsolete systems come cheap.
Forget about upgrading, it's not possible with your Socket 7 motherboard. The PMMX 233 is the HIGHEST END Pentium MMX you can get.
WhereTF do you go to school?
For privacy interests, a "state-funded university"
Surplus shopping is delicious. Government surplus, like state-funded university surplus or state government surplus, is typically a goldmine of supercheap goods.
Police-seized (ie. stolen, and thus expensive) property shows up at my local state government surplus regularly.
I'm sure you could find P3s for $25 at almost any surplus warehouse, though government surplus is tasty because a lot of government agencies are chucking out Dell P3s for newer computers.