The HUE Wireless Dimmer Switch is also included in the version that costs 234.00. So you save another "Stutz" and you have a "bundle", which makes sense with this lamp. The dimmer switch is magnetic and can be attached to the door frame, for example.
I bought this set about 8 months ago and am very satisfied. However, mounting it (alone) is a bit of a challenge.
The dimmer switch costs 26.- (15.01.2019) individually at digitec.
Attention: If the dimmer switch is included, the dimmer switch is already coupled with the lamp and must be installed differently than if an individual dimmer switch is purchased. Instructions can be found online.