I agree this comes down to your priorities. I don't know your financial situation, but I think that in the end the cost of the calculator shouldn't be the determining factor. You could work part time or live meekly for a while to earn the $100-something it costs. Remember your time spent learning is an investment and tools like this can pay out many times over in the future. That isn't to tell you to buy it no matter what, but just something to think about.

Finally, I think you should think about this. After Calculus III (multi-variable) and Differential Equations I (introductory class), computations are less and less a part of math classes. Higher level math classes deal with generalities and proofs and stop asking questions where the answer is a number. I think that it would be easily possible that you would stop using any calculator for the last year or so of undergraduate math study.

That's about every possible thing I can think of on this topic, so good luck