No cost wise it adds 70 dollars to your 280 dollar recertified psu! however at 450 watts each you could install 2 of those at 450w and a single 450-600w psu in the 100 dollar price range and then save 40 dollars which would make up the price difference between the 5770 and 5830
That's true I suppose but seems like it would make for a messy build.