Residential tax is included in price.
I was in an apartment "A4" in June and July 2019 for two weeks and the apartment is really nice and quite big for parents with two children. It is clean and well equipped and there is everything that you need in your own house (dishes, pots, cutlery - all that you need to prepare your own meal) - even cloth pegs. It is a very good base for sightseeing. The host speaks english very well and he advised us which places are worth visiting.