Real world user here, or not user is probably more accurate !
We inherited ours when we moved house with a pretty expensive hot tub left behind by the previous owner.
As others have said the novelty wears off. I didn’t do too bad at using it for the first year but this year I think I’ve been in it twice.
I also drove myself mad for the first 8 months trying to balance the water with a shelf full of chemicals until I discovered a once a week one shot treatment (Aqua Finesse).
As we’ve always had it I haven’t a clue what the electricity costs are but chemicals work out to about £20 a month.
If your looking second hand bear in mind pumps are expected to last about 5 years and most tubs usually have two. I’ve had to replace one at £500 😯 but got away with just replacing the seals on the second one for about £30.
Also all the clips holding in the jet heads perish over the years and fall out. New jet heads are bloody expensive at £5/£10 each considering there are 80 odd in our tub.
If you do go ahead think where your going to put it. Its never the same if you are over looked and Id recommend you buy a cover lifter, you do really want to make it as easy and convenient to use as possible or you wont use it at all!