Call customer service, print the below, and beat them down until they give it to you: http://www.rogers.com/promo/mobitex.html
At that price, even if you cancel and pay the $200 penalty it's still a great deal, so you can't lose..
Read the fine print:
They make you pay $199/$299 up front, but you get a $100 credit on bill for trade in of old unit. Secondly, you sign up for a voice AND data plan, but i beat them down and got them to only let me sign up to a data plan..
Third, you will be on a 2 year contract again..
There is more.. beat them down and make sure they don't charge you a last month on the old BB, or make sure you switch near the end of the billing cycle.
good luck. I upgraded a unit in may with this deal,and one this month, we got rid of all our Mobitex units. =)