One common misconception with a salt water hot tub is that they will save you money when compared to a traditional style hot tub. The idea is that by removing the need for chemical treatment, you won’t have to spend as much money on the maintenance.
A salt water system is generally much more expensive to purchase then a typical hot tub at the start, and the salt water system is usually bundled into the cost of the unit which can inflate the price. These systems also require regular service (whether professional or customer), and because these parts are expensive the service calls can be costly. The cell inside these systems must be cleaned once every three months, and this can result in a lot of time and money. The warranty on these units can also be quite short (ie: 1 year), which can lead to an expensive service bill if needed.
Next time you are looking at a new hot tub, be sure to calculate the actual long-term savings that you will accumulate and perform some research.