✔️✔️ I've always been a rule follower I guess 😁
Very little. 10 minutes a week is about right, tops. When you are using it, just make it a habit to check the floater to see if you need some more bromine tablets, and that takes care of that. A few seconds to stick a test strip in weekly, and if needed, a minute or two to put in whatever it needs. With ours, pH is about the only thing we have to ever mess with, although everyone's water is different. Within a week of a refill, I'll have to bring the pH down. A few weeks later, maybe again. A few weeks after that, and then I usually just drain it and refill it, which is like an hour job, most of which you can be doing something else while you are waiting for it to be finished draining or filling.
We bought ours used. Hot tubs are one of those things not easily taken with you to a new house, or just stored away if you are taking a break from it. So, people will just try to get what they can from them. You can find some good deals on nice ones in great shape. Ours is at very least 10 years old, since we've had it for almost that. Shortly after we got it, It had a drip drip leak when running and I replaced a pump shaft seal, part was like $10 I think and not hard if you are even somewhat handy. Or like anything, if you want to pay someone and just be done with it, it's not going to be any huge repair bill. We painted the skirting too, but that was just because we wanted a different color, took like an hour.
We have a pool too, and while that's not any big deal either like some make it out to be, pool way more maintenance than a hot tub. Hot tub runs on cruise control and stays covered 99.9% of the time, so other than checking the water occasionally, not a whole lot to keep up with.