The cost depends on the size of the room, available floor space, and whether the system is to be used as the only heating source or as a warm floor.
A 5m² bathroom with shower would normally require a 4 m² heating mat and a DEVIreg / ECreg thermostat. For dimensioning of total heating requirement contact DEVI /Danfoss Electric Heating partner in your local area.
Electric floor heating normally costs less in purchasing and installation than any other conventional heating system. The general rule is: the bigger installation area is, the lower the system price per square meter.