I have a Msi N470GTX and I am looking for a upgrade under $150 (as I have recently built another pc). I found a Msi twin frozr Gtx 660 for $130 used and a Gigabyte Gtx 760 windforce for $140 or should I wait (and increase my budget) for pascal and replace my Gtx 970 in my personal system and put the 970 in this sytem