For replacement parts, you can go with 1155 or 1156 Intel parts, assuming you want to stay with Intel. Frys has the i3 550 closeout for $79.99 in today's ad and the 760 for $149.99. Either cpu will run faster than your old Intel core2 duo. I really can't predict what offers you'll get for your old stuff; I would part it out (sell each separately). You'll get more offers. I use anandtech or craigslist for free posting. For the latest, you can go with 1155 cpus, which take different boards from 1156. Newegg carries both types of motherboards with great photos and descriptions. I also check craigslist for used combos. I've gotten fantastic deals from folks who didn't know what they were doing; ordering the wrong parts and having to unload them.