I was a killer bassist when I was 15...people told me, "When you grow up, you're going to be a monster player." I joined the local musicians union when I was 17 and got called to play for The Temptations at one of their local shows. My bass then - a MusicMan StingRay that I found used for $275.
That's the problem with kids today...they want everything NOW. 25 year olds want the $300,000 house NOW. Sorry, dude - attitude like that put this country where it is today.
I'm 48 and still don't play $1500 basses. I have 1 bass that's a custom made but I saved for two years to buy it. Everything else I own (4 basses, 4 guitars, 1 amp head, 2combo amps and 1 speaker cabinet) aren't worth what that one bass cost.
You're 15? Talk to the local McDonalds - car wash - gym - restaurant. Rake leaves, babysit, shovel snow, cut grass, trim hedges. Find some musician friends and get a group together - play some gigs. The work will strengthen you so you can carry your rig and bass up three flights of stairs for a gig that pays $30.
And make as many musical connections as you can. When Brad Paisley (country music guitarist) was a 15 year old, he hung around the Wheeling Jamboree when name acts came to town, asking if he could sit it. Some of the guys would tell him to leave them alone, but he persisted. Today he's one of the hottest stars out there, an incredible player with an incredibly gorgeous wife and child....oh, and makes a ton of bucks, too.
Nobody's going to hand you anything - all your experiences will be necessary for what's in store for your future. Don't whine about it - go do it.
Z