+1 to Jason and Clink.
I played a pretty crude German hybrid before/during conservatory and several years of working. Funny, that bass just sounded better and better, the more I improved

.
For me, my bass was never the logjam...my technique and musical knowledge was. A upper-end Christopher is a pretty nice bass for any student without:
- A trust fund
- An incredibly successful Net-based company that they started
- Very wealthy and indulgent and/or supportive parents
- Deceased relatives who left you a ton of dough
- Professional musician and/or really well-connected parents
- A teacher who adores you enough to sell you a great bass for short cash
Getting a new instrument is a stunning amount of time, money, and effort. Not to say that it isn't warranted from time to time, but it is never a magic bullet...
Know anyone with a Marvin tailpiece? How do you like your strings? How do you like your bow? How is your setup? Carbon fiber endpin? Lots of loving tweaks can make things better, and you won't have to learn a new bass....
Congratulations on playing well at your audition!