Bought a used marquis from a local dealer. 4k plus wiring done ahead of time. Electric bill only went up like 50 dollars. I kept it on year round. He said alot of people who buy the 120 volt units complain that the water goes cool rather quickly as the bubbles release the heat. The chemicals and maintenance were nothing. I changed the water every 3 to 4 months. I'm glad I didnt go for the cheaper alternative and you will too unless money is a major factor.
The guy working had a 10 year old spa and still works good as new. He had no desire to upgrade. Sold the house but miss the tub greatly
