you are absolutely correct, the PSU you are offering is much much price's optimized then any "normal" PSU, no doubts!
but!!!
but, there is a cheaper alternative who are in friendly relationships with a solderer
)
buy server PSU from trusted seller on ebay, say HP 2450W for $60-70, solder there wires with 8pins PCI-E connectors, as many as you need
and here we go, we have a 2.4KW PSU just for a 100$ aprox!
P.S. of course new is better then used, but I converted 3 server PSU already and I know what I'm talking about. this is an option to consider as well!