I have a very similar system except for the new battery (I have two old ones) and I researched in the fall what it would sell for. About $500 tops. But now with the Mac mini out I doubt I could get that. I would suggest keeping the system if it still works fine for you since you won't get much for it. The Pismos are nice machines.
That is a very nice system. I would keep it and invest in Virtual PC 7. Sure, it does not run great but it will run most access tasks just fine. I use it to create databases for my work and they are not small databases by any means. Just a thouht. Plus it would not cost you much at all (assuming yoru school supplies you with Access and OSes as most state schools do). Hope that helps.