Tara, you'd think that working at Ballys would make me an expert, but I only have experience with the training side, not sales.
But I do remember that last year they made a big push to sign up Body Challenge participants when their passes expired. I think you'd be safe to wait until March - bet they'll have a deal then for all the people with free passes. I'm guessing that they're pushing you now because they need to hit their sales number for January.
BTW, if you sign a three year contract and move more than a certain distance (varies by state) from a Ballys, you can cancel. You can also sell some memberships or go on inactive status if it's only a temporary move.