Pricesnightmare

Ok check it,
First off I am a newbe on the site, but have built budget pcs in the past, but this time I am wanting something that can handle all the things that I do. Just happens I do them all at the same time..... The 2.2ghz celeron I am running on an old biostar MB does not seem to like these things....

This is what I was thinking about doing:

Processor: A Socket 939 AMD Athlon 64 3200 venice
Board: Biostar Socket 939 NF4STa9
Graphics:MSI RX550-TD2 56e Radeon
Mem: (TWO) A data 512MB ddr400 simms
Hd: 120GB Seagate Barccuda 7200rpm 8mb cache
and the 80gb I already have,
Case: enlight Gaming PC extreme pa420313
w/ a aspire atx-cw500p4 500watt PWR SC

and the cost I am looking at is around 650 for the tower alone.... Any Sugestions??