This one I picked up for £20 at Halfords, although this particular tool kit is normally around £30. Like most of its kind, it's uses are limited for most plastic modelling jobs, as the lowest speed is 8,000 rpm, with highest at 18,000 rpm.
The Rotorcraft range are available through most major model shops/outlets, and Model Hobbies in the UK can do it on-line and ship world wide if you have problems finding one.
With a lower speed, I would probably use it more, but even for drilling, in plastic, any power tool can sometimes be 'overkill'. Good for other modelling jobs though, especially with non-plastic materials.
Oops! Just noticed - you wanted a cord less - this one isn't !