Wow, that is an awesome deal.
Just add another stick of 512mb memory and you have 768mb of memory to power your computer for around 100-150$, which is a great amount of memory and will power anything with no problems.
The processor and harddrive are pretty good, and with a good video card inside of it, that would add around 100-200$ to the cost, so overall you would have a powerhouse computer for just around $500, so yes, you got a great deal
Just curious, but how did you actually get that deal?
A friend, a store, online........ ??