See, this always kind of confused me. When you're buying a new CPU, most people admit that you won't really see big differences between a lot of CPUs
right now in terms of performance (past a certain threshold, obviously) as most will get you over 60FPS in a current game.
But when they're older, people say it's not worth just upgrading the CPU as it's better to buy a new MOBO and CPU instead. So is there just a sweetspot of a year or so when it's good to upgrade a CPU? Or when it pays off to have bought a better one?
That's kind of what I'm looking for here

-- among other things, like where to find one for a good price. Do all LGA1156 MOBOs work with all 1156 CPUs, or should I be looking for something else as well?