We purchased a 6-man Coleman tub from Keller Hearth & Home in Mandan in 2002. Only major issue we have ever had was one of the two-speed pump motors quit operating at low speed. Evidently the controls were smart enough to know this so rather than let the water stand idle and freeze things up, the pump just shifted to high speed. I was able to tell that things were amiss by the sound of the high speed pump running continuously.
But as was said, the novelty wears off eventually and they don't get used much. We enjoyed ours the most in the winter as long as the wind wasn't howling. In 2014 we started spending the winters in Texas so rather than worry about the tub freezing up, I started draining it in October or November and then refilling it again in the spring. This past spring I elected not to fill it because we had a busy summer planned so it is still without water. If anyone was interested in buying it, we might be willing to sell. Not sure what it might be worth.
Chemicals are expensive but as long as you are careful, you don't go through that many. We have a private backyard and usually use it after dark so seldom wear a bathing suit. When company come of course everyone does but I do notice the water getting a little cloudy after such use. The experts blame that on laundry soap residue in the fabric. It does help to have a good washer that rinses the clothing well.