As an analogy: when I first started kayaking, my more experienced friends said I should get a "real" paddle, not the junkers that came with my rec Hobie. I tried theirs, and I just wasn't familiar enough with paddling in general to really tell the difference. A few years later, I scored a great paddle on sale, still not thinking it would make much difference other than weight - wow was I wrong. I kept the Hobie paddles as "back of the boat" spares, but other than that, I'll never use those oversized soup spoons again.Learning on a learner serves several purposes. In a way I look at it like wearing ankle weights and training for a marathon. If you enjoy playing and progress naturally, getting a quality bass that suits your needs will be like knocking off the ankle weights.
If you outgrow this bass, you'll know enough to know when you do, and know what you want next. (even shorter way to say it)