If it was me, I’d change the memory to 16gb and do nothing else until you can afford to make complete step change that’s really noticeable. You’re happy with the monitor and presumably keyboard and mouse? If so, James recently dropped £1500 (?) on a good rig...save a bit more, maybe get some birthday donation dosh, etc and wait until you can afford the next level up because a grand is a lot to drop for a small improvement IMO