So to start with a bit of background, I went to Japan in October 2015 for an exchange program. Didn't know any Japanese and learned from scratch there. Come July 2016 I decided to take the JLPT while I was there and passed the N2 (just barely, probably not a good score to bring to an interview).

Now that I'm back in the US, I'm considering continuing Japanese classes here. I took the placement tests for the Japanese department and got placed into their Advanced course. The textbook they use will be Tobira.

However, this isn't something that is required for me to graduate, and am basically just doing it out of interest on top of my other 5 courses this semester.

My main question is, is it worth buying Tobira for 89.50 USD for a class which I may end up needing to drop to keep up with my main classes? I know the Starter's Guide recommends Tobira, but I'm not too sure about it's effectiveness as a self-studying tool. I might be better off just looking at JLPT books for N2/N1 and studying those instead. Any thoughts from those who have used it in either a classroom environment or as a self-study tool?

If I decide not to buy the book, I will just not take the class. It isn't a big deal since the main reason for taking classes here is to have somewhere to actually use the Japanese I learned, mainly speaking, aside from the occasional contact from professors and students in Japan. Doesn't seem to be any places I could go practice conversation in Oklahoma, although where I can go looking for places to converse in Japanese is a different topic.

Thanks for your input in advance! よろしく！