Thanks for the feedback!
When I called, I was told that if I purchased tix through them, I'd get free parking and TTMM vouchers. They didn't specify that it had to be part of a package, so I'm hoping that's not the case, because I've already booked my hotel (off-site) separately.
And naturally, their offices are closed today and tomorrow, so I can't ask them. I wonder though, if I just go into an office to purchase the tickets (I think we did this once for Sea World in Ohio, a million years ago...), if that would solve my problem? I'd have the tix in hand right away.....I think.