Get better ram for this $400 build?

I have already purchased this build: http://pcpartpicker.com/p/LkL7.

I found some 8gb 1866mhz ram for $45. Should I return my 4gb 1600mhz ram and upgrade to this?

Thats $469.86 build...

You must be more specific when you are saying what your budget is...

No just over clock your ram if you whant 1866mhz 

yes go with the 8gb will be better for you.

why send back 4gbs and buy 8gbs when you only need to buy 4gb more? and its going to cost you to send the 4gb back to O_o

what if its cheaper the way i said it