Rachel,
My old computer was 8 years old when she died (RIP), My parents finally moved what was the family computer into my Room and I inherited all the problems with it...Yey. Anyway I got my new machine Costom built locally for around $1,100 It is A pentium 4 300ghz with 496 MB of RAM, It might not be the Very Best you can get, but it does what I need, and it sounds you are very much in the Same boat
It will play your sims, music, allow you to surf the Web and other stuff . Maybe it's worth looking into
Jake