Alright, there is an updated build with a better cpu, more ram and a larger HDD. I know you said $800, but shipping is getting kinda expensive. Still, you might have a little bit left over depending on the shipping. If you want to squeeze the last bit out of your $800, then I would get a better CPU like a E8400 or if you want to really push get a HD4870 instead of a HD4850 but the HD4850 should handle Bioshock fine.