If you are going to be tossing your current computer in a few months, I wouldn't bother burning money on it now unless you need to replace a dying CPU and need to bring your existing system back to life until then, though this could also be an argument for upgrading immediately instead.
A used i7-2600 still costs ~$100, may not necessarily be in great/usable condition, could even be fake. Great if you get a good one on the first try, not so much if you don't. Worst case, a bad CPU could ruin your motherboard.
My i5-3470 is rock-solid (107 days of uptime, a bit overdue on updates) and I wouldn't risk sacrificing stability for a few months of ~30% better performance in multi-threaded workloads. (I have an i7-2600k sitting on a shelf because it crashes every few days on my Asus H77M. Thankfully, I got the i7 for free as compensation for attempting to unbrick my friend's motherboard, which I couldn't do because his EEPROMs were completely burnt out from a failed flashing attempt - thousands of cells were either stuck or intermittent.)