and another thing that everyone here seems to agree on...the cost up front may be higher than you'd like to spend, but still small compared to the cost of repairs later on if you get a 'cheap' tub or try to cut corners where it counts.
the value, however, is not just a dollar amount, but the peace of mind of having bought a tub from a spa dealer that will be behind the product you finally purchase throughout the warranty, and after.
Find a reputable dealer in your area to discuss your wants and needs with. You may find that the stereo being part of the spa isn't necessary (they're VERY not cheap), and you can "make do" with a bookshelf style stereo, or boombox.....Many spas have "cool" lighting, and I saw a post that told you of the availability of a color changing LED light. That might be the cheapest way to go, without giving up on the idea. Ask if the light changing package is extra on the tubs you look at, to be sure.
Water features.....waterfalls, etc.....some of them run the prices of the tubs higher, but plenty of the people on this forum find them overrated.
Aromatherapy can be done by simply buying bottles of Spazzaz or other scented crystals or liquids. Use in moderation, however....there's also a fish that you can fill with the scented liquid, and it releases the stuff at a 'slow' rate...
Also, the tubs are listed at 2 voltages.....115 and 230, I believe.....the firstb plugs in to an outlet, but apparently doesn't allow the use of the heater and jets at the same time. This may or may not be issue for you.
Just a few things for you to consider that could help you figure out what's important and what you could cut costs on.
Best of luck!!