how big of a power supply would i need? Will this system let me play newer games? not the bran newest on the best settings but newer games and the new stuff on low settings... How easy will it be to upgrade as the time goes on?
This fits under your budget if you reuse your ODD and HDD and get a cheap case. No it wouldn't play new games to well, but once you get more money you can throw in a video card. It should work for a little while if you have a small, low resolution monitor. Your budget is really, really low but that's the best I could do with it.
That looks good to me as well. You need about twice that budget before you are going to build what most people would classify as a good/decent system. That setup I would classify as more of a 'just to get by on until I can upgrade' type of build.
The bad news is: even the el cheapoest AM2+ seems to run ok with lowest DDR2 667 so DDR2 400 will screw ya over Good news: if you can salvage ODD and since HDD is fine something possibly within your reach which would cut it for 1280 x 1024 or 1440 x 900 with toning down of settings perhaps depending on game?