What about case, OS, HDD, monitor, keyboard/mouse. Do you have any of these?
At your price-point I'd be looking at no GPU to start with and relying on Integrated Graphics.
If your budget is too low, you will end up with a bunch of cheap/old/low-performance parts.
I'd plan a more expensive system and then work out how to get there from here. In particular, to protect your future investment, you NEED a good power-supply. A bad cheap power-supply is capable of destroying your system.