Wow ! Congrats and it is really beautiful.
The thought has crossed my mind. The good thing with at home projects is that you can compensate for mistakes/ unexpected challenges and still have a quality product. A professional piece really needs to have very minimal flaws. So for that, we'd need a handful of professional tools that can produce super precise cuts and pretty much perfectly squared pieces. I think those things are probably the main issues when it comes to woodworking. And the bigger the project, the more important these things become. Right now, I can get 'close enough' but not at the level for a high priced item. I think the $10k price tag is probably about correct, probably a bit more if some really nice hardwoods like mahogany, walnut or maple were used. As a comparison, you can see here that spas are willing to pay $20k+ for a custom-made heated salt bed (the 20k is just for the shipping!) So, maybe at some point!Fantastic job! It must take a great deal of skill to make a machine like that, so congratulations.
Have you ever considered the possibility of building more of these for sale? The only comparable equipment I am aware of are the whole-body beds such as Thor which can sell for up to $100,000. If you were to sell these at a much more affordable price (maybe $10,000), then more people would be willing to buy them and then this could bring in a significant source of income? I am not sure about the logistics of how you would transport them, or health and safety regulations etc. But it may be worthy of consideration for the future.