I joined and I liked it but being a student I just didn't have the time to drive there often enough to see results so it lapsed.
In my experience you don't see Curves places offering discount memberships. The best you can usually hope for is having the sign-up fee waved and I would ask about that/hold out for it. I think my Curves was unique because they offered a $100 for 4 months plan if you had university ID. They knew they were competing with the campus gyms so it was in in their interest to offer a cheaper plan that wouldn't be sitting unused if the student went home for the summer.
I never did the weight loss stuff, I looked at the material and it all seemed pretty common sense to me and a way to push products but someone who tried it might say different. Our Zumba classes were once around the circuit in 1 minute increments instead of the usual twice for 30 seconds and during the cardio portions we did Zumba. Those were $2 a session.