I was initially going to purchase the e8400, but I need to tighten up my budget so that I can afford my college tuition. Is the e8400 worth the added $70? Will I still have good frame rates with the e7200 that won't hold back the power of the 3870x2? I don't plan on over clocking, but if I do push the e7200 to 3 ghz will I need an aftermarket cooler?

I'm a gamer, by the way.

Well starters if it does limit the E7200 I doubt it'd be buy much. The extra cache of the E8400 means it will have about a 10% advantage over a E7x00 at the same speed in most apps so unless your performance crazed it shouldn't be a problem.

As far as the overclocking goes I always say aftermarket cooling on a CPU for overclocking but I'm just paraniod about heat.

If you are doing any type of OC, I would recommend the "El Cheapo, float like a butterfly but sting like a bee, big punch in a small package" - Artic Freezer Pro7, ($25) since you are on a tight budget.

Once you hit the 3ghz mark, you won't be bottleneck much by your CPU anymore.

I have an E8200 at 3.1ghz and 3.5ghz with 8800GTX. Trust me I dont' see any difference visually or noticable frame drops at 1680x1050., unless I run benchmarks to show me the difference.

No worries. The E7200 will keep up pretty well, especially at higher resolutions , and even better when overclocked. Of course there will be games that depend a lot on the CPU, like FSX, but I think you'll be fine in most games.