Mac Pro Desktop - Model MA356LL/A MacPro1,1 Dual 5150 2.66GHz Xeon CPU 250GB, 7200RPM Hard Drive 6GB RAM 1Gbps Ethernet NVIDIA GeForce 7300 GT GPU Clean Install of OS X 10.6 Is this worth $225? I wanna buy it to replace my rMBP. The rMBP is just too much power for me. I only need to type documents and surf the web. I already have a display, keyboard, and mouse Is it worth it? What will this machine be able to do?