Renting to own a professional bass

So I've been playing Double Bass for a really long time, but I've never looked into a professional instrument until now. I've been renting to own a bass from Lisle Violin Shop, and I have heard from my bass mentor that if I'm not happy with my home bass (A 3/4 Christopher Laminated Bass) I should look into buying a professional bass from a luthier. I have checked the luthier directory, but I have failed to find one that offers a option to pay monthly since I don't have all of the money at once.

Yes, I know it will be expensive, but I'm a highschool student that is getting closer and closer to going to university and I need to get a better instrument. Any help, bassists of houston?