+1 to everything already said, especially @Wombat-metal and @howard ‘s advice. Don’t set a target, set a budget. Your tastes will change and evolve.
Personally, I’m a big fan of Reverb.com for used gear (and I always try to buy used if I can), and Sweetwater for anything new.
Guitar Center is useless to me. I play left-handed. GC and music stores within a several hundred mile radius don’t stock lefty gear, especially the higher dollar stuff. Everything is bought sight unseen. And I’ve had great experiences, even with a couple of $3k+ guitars. I have no qualms about it these days if the Reverb seller’s rep is solid.
So, yeah, learn bass on what you have. Fill your “I Want a F*cking Cool Bass!” account without any preconceptions. Check out the Show Us Your Basses and Bass Porn threads just to see what’s out there.