Is there such a thing as your last guitar? Of course, if you die, that one was the last one, but as long as we live, we will find new reasons to love different guitars. We just have to learn to be content with what we have.
Just remember...once you get above budget junk...good sound is all in the fingers and not in the guitar. To get that you need to keep the one you have...for the more you play it the cleaner it will sound.