Purchase. There are three tiers, and each buys something different. Our portable butt shower costs €19.90: a bottle you fill yourself. Our non-electric bidet seat, the New Standard, costs €99 and stays fixed to the toilet; the water is warm if it is also connected to the hot-water pipe. Our electric seat, the Deluxe, costs €249, heats the water itself, and adds a dryer, a heated seat, and a remote. You choose the hose length to suit your bathroom; the price stays the same.
Installation. As a rule, zero. Old seat off, bidet seat on, T-piece on the angle valve, done. If your device mixes warm and cold, a second T-piece goes on at the washbasin. Tools: a screwdriver. The one exception: the electric seat needs an outlet within reach. If there isn't one, an electrician comes into it – and that is then the most expensive item on the whole bill.
Water. One fill of the portable butt shower is 450 milliliters. At German water and wastewater rates, that's a fraction of a cent. A seat uses a similarly small amount, depending on how long you use it.
Electricity. Only for the electric seat. How much depends mainly on whether the heated seat runs all the time or only when needed.
What you no longer need. Most of the paper. One sheet is usually enough for drying, and with a dryer not even that.