I have a Toshiba Quosmo X505-898, running CS5, under $2k. I edit with the XDCAM-EX timeline without issues. An external SATA raid is helpful, but not critical. Obviously, the more you spend, the faster your renders are – so it depends really what you are trying to do. There is a CS5 Premiere Pro benchmarking site you can Google. My Quosmo is on the list – so you can check out the results yourself. Good luck!