It says so $10 for 10MB on Roger's Website -- it's a special but I think you must already have a voice plan. You forgot to click the link in my FAQ:
[*]Q: Why use a non-BlackBerry data plan on a BlackBerry?
A: As one example using Rogers Canada, see the price comparision: Rogers Mobile Internet versus Rogers BlackBerry Plans
...$5 for 5 MB of non-BlackBerry data
...$10 for 10 MB non-BlackBerry data
...$45 for 7 MB of BlackBerry data.
As you can see, you can get a generic data plan for BlackBerry for less than one quarter the price at this Canadian carrier! Another reason is to be able to use a BlackBerry with a carrier that doesn't support BlackBerry.