I agree with you about the amount of RAM. I have 4GB and, with all the things I have runing at the same time, I normally use more than 3GB, leaving me without enough RAM to play smoothly. And the difference in price between 8 and 16GB are quite small to not jump directly to 16.
And that's what I've done, waiting to get my new 16GB of RAM with, btw, has cost me the same as the 4 GB I bought 2 years ago.
About the difference in cost between buying the parts and building the PC yourself versus buying an already assembled PC, at first it may seem not worth it as it can cost you almost the same, but the next time you upgrade the cost savings starts to appear as you no longer have to buy certain parts, like the case, PSU, HDD/RAM, etc.
Please excuse my bad English.
Former gaming PC: i5-4670k@stock (for now), 16Gb RAM 1600 MHz and a GTX 1070
Current gaming PC: R5-7600, 32GB RAM 6000MT/s (CL30) and a RX 9060XT 16GB
Steam / Live / NNID : jonxiquet Add me if you want, but I'm a single player gamer.







