If you don't already have one, and you are already done with gross, I definitely wouldn't waste the money.
1. If you want to use it, they definitely will have multiple copies in the library.
2. If you want to buy something, your money would probably be better spent on a good neuro atlas which incorporates pictures. Ask at the bookstore. Keep in mind these can be found for free in your library as well.
Do not waste your money on Rohen for neuroanatomy! You could easily find general, gross pictures of the brain online for free. However, you should definitly buy Haines especially if your course requires you to identify structures on brain/spinal cord sections.
I'd look over Rohens for major gyri/sulci and such for practical exams. It's pretty good. It was nice to review stuff in color. Haines was usually the bulk when it came to learning tracts/nuclei, though.