Do you jump into things head first or feet first? Head first, get a kit. Anyone good with instructions and patience can build a kit.
If you intend to race, check out a local track to see what most others are running. You'll get a lot more help if people are familiar with your car.
With your budget, I'd buy used from this board. There are tons on deals here. Figure out what type of car you want first though. Take it apart and rebuild it once you get it to understand the construction.