@Huma0
Re the dressing gowns, I would say 99% of guests use them and they also get mentioned in the reviews as an added bonus.
I suppose I tend to put things into my listings, that I would like if away on holiday myself & I think for hot tubs, especially in winter, a dressing gown is a must. Getting out of a Hot Tub on a frosty night is not fun if you haven't got something to snuggle into straight away ! I must admit, I wouldn't provide the dressing gowns if we didn't have the Hot Tubs.
Re the laundry, yes it does add to it in a substantial way, but although I love soft and fluffy towels and dressing gowns, I now simply refuse to use the tumble dryer. So everything in winter is dried on the Aga rack or in Summer out on the washing line, so it is not an added cost to dry them.
I hope I have the balance right regarding price & a little luxury but I must admit those things are constantly changing in today's world, what might be inexpensive one minute, costs a fortune the next !