My Hack cost $1155. How is that more expensive? Unless you don't have a monitor.
I have an ATI Radeon 6870 2GB. It has a minidp port and I can use our old 2009 27" iMac as a monitor.
Edit so people stop complaining I didn't include monitor costs:
The iMac with the 3.4 i7 and 2GB 6970M is $2299. That's the 1TB HDD 4GB RAM version. Even if I bought the Apple Cinema Display for $949 off Amazon I'd still come in at around $2100. I have an i7 2700K 3.5, 16GB RAM, the 6870 2GB, 4TB HDD, a 120GB mSATA SSD for OSX and a 128 SSD for Windows. Now compare.