Of course server psu's can be cheaper. I have been researching them, but there seems to be too many variables to work out, or I'm overcomplicating things. Most every full guide I see shows using a 750w psu. I need my ants running at max gh/s no matter the extra cost of power because my power is cheap. And the 750 won't allow me to run 2 fully oc'd.
Check out the Gigampz breakout board (
http://www.gigampz.com) for the HP DPS-800GBA server supply. It's the same supply that is compatible with the ASICMiner back plane you can get them for cheap on ebay and you don't have to do a bunch of soldering or anything crazy to get going with them. Each supply can easily power two overclocked AntMiner S1's. You power supply costs per Ant will be about $30 total.