Any type of major purchase usually comes with an option to upgrade the basic model or just go with the deluxe. Extras can add up very quickly, but knowing what you can or want to spend, and how much luxury you need in order to get the most out of the hot tub experience will help you get what you want with fewer hidden costs or the need to omit features.
Before hitting the sales floors to browse available options, take a look at hot tubs online and decide on your essentials and non-essentials. It may be easier to turn down colored mood light, prime built-in sound equipment and waterfall features if you've seen them ahead of time.
Basic models provide the benefits of hydrotherapy, and that may be all you're looking for, but if you want the full sensory experience for enjoyment and entertaining, set a budget to include the bells and whistles that will make your hot tub exactly what you want it to be.