Just curious joni, where did you find that tank for $163? The gas model typically retails for $550-$600. If you found it online through a third party seller, you will want to be sure that the manufacturer will still honor the warranty, the tank isn't already used and that it's not a bootleg version of the original tank. Just looking out for you. Rheem makes GE tanks. If you can get a model and serial number of the tank before you purchase it, their customer service may be able you verify that it's a good warrantied heater.
Rheem customer support: 1-866-720-2076 Available between 7AM - 7PM Central Time 7 days a week