Tai Chi Studio is such good business lot idea. My sim purchased a lot as a gym and originally, her asking customers to join her in tai chi was to keep them busy while all the treadmills were in use, but it actually works even better. Their energy goes up, they eventually get hungry and lose hygiene after several hours, but all other needs remain static. I'm charging §20 on the bandatron. My sim has owned the business for only 3 days, made thousands, gained fitness, and gone home with full energy every night.