The Normally Uber expensive rapid charge dock that uses the rapid charge soft socket and saves the strain on the USB connector is 29.00 at Walmart.
I can't find them for under 69.99 here in Canada .
For the Canadians interested you can pay through paypall and nip over the border to pick it up if you are in a border town or close.
Walmart.com: BlackBerry PlayBook Tablet - Rapid Charging Dock/Stand: Computers