I bought a 3DS 5 days ago to get into the ambassador program. I asked the guy at Best Buy if I would get the price cut guarantee and they said I would. So I'm all good!
FYI, Wal-Mart is lowering the price on the 8th or 9th, so you can get the system for $170 in addition to getting the 20 free games, assuming you get online with it before the 12th.