If you happen to live near the mexico border dental care over there is extremely cheap. $20 cleanings, crowns half the price of US at the same quality or better. Naturally, research the office, but there are a lot of good ones. If you needed major work flying down and getting it done is often still cheaper than staying in the US.

I personally dont have any recommendations for whitening, but it might be worthwhile to get a cleaning and an exam. As expensive as it may be, waiting is far more expensive. I learned that the hard way.