I got a sweet deal on a 1250X Seasonic modular gold rated PSU. My system will have SLI 970 and a noctua nh-d15, so itll take a 750~850 PSU to handle it. the question is if I can get a 1250 at the price of a 850 modular one at the same grade, should I go for the 1250 or it will hurt my electricity bill?