Upload & Sell: On
Just to throw in my 2¢:
The amount or RAM and the drive speed are the two most critical factors for PS use. It's not the CPU or the GPU. The GPU hardly gets used at all in PS - for editing and processing photographs. Tested, there's like zero difference between an ancient 7300GT and the new GTX 690 screamer! - even when batch processing hundreds of files. The CPU becomes more important if you're running scripts and batching files but if one were to time a person processing 5 images one at a time like most of us seem to do, the times would not be significantly different between someone with an overclocked desktop and someone running on a laptop corei5. Maybe 20s or 30s difference at the end of the 20min. test - not significant - and given they both had 16GB or ram and an PS configured SSD or SSHD it wouldn't feel sluggish to either user.
IMO, I think 8GB is not enough for editing RAW images from modern cameras. It can be good enough even overkill for typical jpeg processing but people processing RAW images usually also bring in the files at 16bit. Processing more than a few of those or doing panoramas etc., gobbles up RAM pretty quick. So between the OS and wanting to preserve its RAM based caches, the PS app itself plus plug-ins, and the size and depth of our RAW IP sessions, 8GB doesn't always cut it. Anything between 16 and 32GB is a nice safe zone - typically speaking. 32 is better IMO and 64 is better than that but only "better" (over 16) when atypical usage profiles are considered.
PS also spends a considerable amount of time fishing on the hard-drive for this and that so having the OS, PS, and the PS scratch partitions on fast media also has a noticeable impact on performance. Again more-so than the CPU and a gazillian times more than the GPU. Of course you also want to have the scratch partition on a different physical drive than the PS app resides on - the difference there is almost 2x average speed difference in every situation when/if the scratch is employed during a session. Even with 16GB it gets hit from time to time. And when it does, OMG do things slow down - even with an SSD as your scratch.
All that said, after you have enough fast memory and properly tuned SSD/SSHD's one can squeeze a little more out of it by using fast(er) multi-core CPUs and a fast GFx card is useful for other things - like fragging n00bs...
Anyway, I guess I've spent a nickel already so being 3¢ over budget I'll leave it at that.