Yep, CAT6 is only about $100 for 1000feet, CAT5E is only about $80 for 1000 feet. Both will run at Gigabit speeds, but if you're looking to put it in the walls and it's going to cost a lot. Might as well use the better cable. Possibly even use CAT6A (rated at 10 gigabit). 3 times as expensive as CAT 6 though.

I like my SSDs too much to go with refurb desktops. I also use things like Intel PXE to install Windows 7 over the network.