I subscribe to the "garbage in, garbage out" school of thought with respect to upgrading. Start at the front and then work your way down the chain: source, preamp, amp, speakers in that order. Good downstream equipment cannot add what is lost upstream. The best that it can do is offset an upstream deficiency. It's better if there is no deficiency to offset, or as small a one as possible.
Now if you happen to come across a good piece of gear at a good price, I would also suggest that you be practical and take advantage of the opportunity even though the upgrade may not be in the right "order". This presumes, however, that the upstream components will be upgraded shortly thereafter. Otherwise, you're spending money on downstream components whose potential will not be realized without correspondingly good upstream components. A bit of a waste of money.
By the way, you have said some dangerous things.
"I can not stop upgrading".
Also: "I am relatively new to this hobby and have heard many things".
I am a bit worried that you don't know why you're upgrading other than that it seems to be the thing to do. You haven't really identified what you're unhappy about.
Step back and take a deep breath. Your pocketbook will thank you. If you just go out and upgrade without a clear plan, you are likely to buy something which doesn't do what you hope it will do, or you will not hear it do what other people say it will do. This will turn you off to the high end very quickly.
Take you time and learn a bit. Ask yourself what you're unhappy with before upgrading. Research some threads and get a feel for the character of equipment you're interested in through the experiences of others, And most importantly, listen to things yourself at your local stores. Then you can begin upgrading with a clear idea of what you want to do and what equipment might be the best match.
