You don't need (and i dont think your motherboard supports the 1866mhz memory) you can stick with 1333mhz, and get similar performance within a percentage point, that will save you a bit.
Unless you plan on over clocking: first you can get an i5 3470, then get a non z77 board, and get rid of the 3d party cooler. This will save you a bit, but if you plan on overclocking then you will see a bit more performance per dollar.
Your PSU doesn't need to have that much power a 500w would work fine, though there may be nothing at that price point cheaper.
Unless you know you will be using CDs or DVDs you don't need a disc drive anymore even thing is all in the cloud download now.