The main reason to buy solar operated hot tubs is to save money. If you are worried about the added electricity costs of purchasing a hot tub then maybe a solar powered hot tub is for you. Hot tubs are not cheap and you should always consider that no matter what kind you get.
Now, before you get one, you must understand that you will be spending more money up front for your hot tub. How much more depends on the type of unit you buy. Over time you will be able to save money on electricity, however, and that should more than make up for the up front cost. You should know that you will be keeping and using your hot tub for a least 5 years before you can expect to make up in electricity savings what you spent up front to get the more expensive solar powered hot tub.
The other main benefit to the solar hot tub is that it uses the natural energy of the sun and a lot less electricity. Saving electricity means saving the environment and helping lower global warming. People who are interested in off grid living will be those same people who are interested in solar heated hot tubs. When you get a solar operated hot tub you can know that you are doing your part in helping to save planet earth.