landsavage :
Trying to keep it to <= $7.50/GB. Looking for 8GB, preferably in a 2x4GB config, though I would do 4x2GB if the price and quality was nice. Just more efficient to upgrade the 4GB sticks later (have 4 slots).
Also, what's the suggested speed? I was thinking to keep it to 1600-1866, anything higher seems quite expensive.
This is mainly a suggestion thread, I am watching pcpartpicker daily for deals.
Regarding Speeds:
Note:
"The memory controller is integrated into the AMD processor. The maximum speed supported varies by processor family and is also limited by the amount of memory slots used. "
FX series processors support 1866MHz memory but whether it may run @1866MHz depends on the number of slots being used. If you use just two slots then 1866MHz will run at the right speed else it will be downclocked automatically.
Keeping the speed limit in mind, I think you should go with 2x4GB rather than 4x2GB modules. Firstly, it will enable your system to run @1866MHz if you choose to opt for the same. Secondly, you will have two empty slots which can be used for further upgrades without having to toss any of the existing memory. Thirdly, installing more modules will cause stress to the memory controller so 2 is better than 4 (this doesn't apply when you are trying to max as there is no way to max it unless you are using all the 4 slots).
Yeah, try pcpartpicker. If you would like then check other sites as well you may find nice deals .. newegg or amazon or other sites like kingston, memorystock.com
If you are going for memory with heat spreaders then try GSkill Trident > Ripjaws z or Corsair or Kingston HyperX. Hope I've answered all your questions
Good luck with the upgrade!!!