I believe thats the price for only a single FX-74, while you need two of them to use 4x4.The AMD FX-74 is seen ffor only $407- at http://www.newegg.com/Product/Product.aspx?Item=N82E16819103866 Meanwhile newegg is having 4th of July specials running on other items like board/cpu bundles and cases.
FX-74 is a Socket F 1207, why would you want that in a desktop. You can get a AM2 socket Athlon 64 X2 6000 for 216 bucks. there both 3 GHZ and 1 mb L2. There both close at there limit at 3GHZ so one wont overclock any better than the other even if the FX has a unlocked X.