well he spent $150 upgrading an existing pc, but still not too bad. if you dont mind using some used parts then your budget would just about manage a gaming pc to play basic games or low settings. maybe try part picker or something similar to put together a build around your budget. at this price point it would best off being an AMD build simply due to low cpu prices.. maybe an athlon or similar and i have the asus version of the gt440 gddr5 which only cost me the equivalent of $60 brand new. in terms of power, if you arent doing sli/crossfire (which you wont in this price range) i cant see you needing any more than 300/350w or thereabouts (if possible go for well known brands like corsair- im not an expert in psu's). gigabyte do pretty decent budget boards for your mobo but make sure the cpu and socket on the motherboard are the same (eg AM3/AM3+ for most AMD processors, maybe other sockets for older cpus) and 4gb of ram is pretty much all you will need