at the site
Garmin | Garmin Mobile after going to the Blackberry section, you can see it says "as low as $99" for a one year subscription.
If you go to
Handmark | Garmin Mobile Monthly Subscription for BlackBerry its billed as $9.99 a month but you can get your first month free and are able to cancel billing within the site (something that I can confirm because I've done it myself)