I want to make a memory upgrade for the 2.93 core i7 iMac. How will i choose the memory modules needed, i mean what specs must i be looking for? Right now it has 4GB (2x2GB DDR3 1333mhz).
Im thinking of placing 2x4GB
One company over-charging? Especially assuming you mean the outrageous prices apple asks for their BTO RAM. It's a relatively cheap thing to find these days. That RAM should work perfectly fine.
Yes if that were a factor but it isn't in this case. The RAM posted in the links is exactly the same, spec wise, as what apple puts in. It's just a different company making it.
Apple prays upon people who don't realize how much RAM actually costs / how easy it is to install and they get away with it a lot. As long as people continue to buy it from them they'll continue to charge more. They claim it's "better quality" but in actuality no one would be able to notice a difference.
I can't recall off the top of my head. If you want good quality RAM that is tested and warrantied to work with macs though I suggest OWC RAM. It's what I always install in my machines. Works just as well as Apple RAM at a fraction of the cost plus, as mentioned, it's guaranteed to work for your exact mac model.