Well, could be but I used PS from 3.0 to CS2 professionally and we managed to do everything needed with those too. I owned almost all versions but only have the CS2 package left. Haven't used newer ones so I cannot miss any of their features. Not a fan of Adobe as a company anymore, greedy b..tards. Had to do some googlejutsu to even get the PS CS2 back running again.
If something, I would like to get PS 7. Haven't searched for it, I am sure it can be found but I don't have my serial anymore (or don't know were it is). EDIT: found it in Mac repository. Now I need to search my storage boxes for old disks etc. to find a serial.