My supplier can source very similar switching supplies for around US$25 or so.

And a local surplus shop here has the unversal kind, 12V-3.5A, with the right tip on the connector, for C$20 right now. I bought one, works fine, power to spare (but not wasted, since it's a switching supply). 120/240VAC, 50-60HZ. Requires a standard computer style power cable (three prong).

I have thought of offering these with the docks, but was unsure of the demand.

Cheers