One time I bought a used Blackberry from a private seller, but I did not want the data part, I just wanted it for a 'push-to-talk' and it was a really good price. I took it to Telus to sign it up and they said I HAD to get a data plan since I had a Blackberry.
I balked and then a manager told me to bring the phone back after a few days (like 14 I think), and he would just change the sim card to trick the system into thinking I switched to a non-Blackberry phone, and he would take off the data part of the plan at the same time.
That was great.. but the difference was that I owned the phone outright already, before entering the store, and didn't have to be on a contract. When you're getting subsidized, you are in effect paying for the phone over the contracted period instead of up front. Works out great if you know you want to be locked in for that period of time, not so good if you don't.
Seems we can't have our cake and eat it too.