I would hope they have some sort of policy in place. Although something like a car dealership, they might just laugh at you and say you're sol, but I have had experiences before when I bought something, a big ticket item, and then two days later it goes on sale. I've gotten the reimbursement. Now of course this wasn't a car, but like everyone else said, if you don't ask then you don't know. And it is true that if you are willing to walk away, then maybe they will try to appease you instead of lose you all together. I am always in the mind set that if you can save the money then do it, but that's probably because I don't have any money .
Ultimately, although waiting can sometimes be a pain, I have found that it is usually best in the end. Nothing bad has come out of having to wait a couple of months longer, in at least my own personal experience. We are often so eager and want things right away, but waiting a couple of months will most certainly not kill you. And you will financially be better off for it and won't be kicking yourself for years to come.