Funnily enough, this thread has had me thinking about how for so long I had to sell my main bass to replace it with another one, and never had more than two basses at a time. I was always looking to get a "better" more expensive bass than the one I had and that was the only way I could afford it. That was probably true for the first twenty years of me playing the bass. I expect lots of folk have followed the same route with similarly mixed results.
Nowadays I just like a bass that I can have fun playing, and that could be at any price point. The problem is I'm one of those people who has been cursed with good (expensive) taste, but I've also got a Sire and a Harley Benton that I do most of my day-to-day practising on and they are both very satisfying basses and amazing for the money.
I think when I reached the stage in life where I could comfortably afford more expensive basses it took away the imperative to "upgrade" before I missed the chance. That realisation helped me concentrate more on practising playing bass rather than putting time and energy into trading up to endless,"upgrade" basses and then discovering their strengths and weaknesses. Most of the time I was just swapping one dissatisfaction for another.
If you've got a relatively inexpensive bass that has certain things about it that annoys you it's easier to live with than if you have paid upwards of three grand in pursuit of perfection only to find disappointment.