Just went over this about a couple of months ago in my business law class. Usually, it depends on the state law and wording of the add. Usually, if the add says prices subject to change, that's enough to get a business out of a price. Alternately, prices that are obviously erroneous are usually unenforceable as well.
In your case what might have been decided is that they were deliberately being misleading with the price (by only listing a payment price, and no accompanying retail price or notation for monthly installments). If the add said $360 you might not have been able to get the deal (dropping a zero a very possible mistake).
Either way, great deal (and if I were you if allowed I'd still try to get 2
)