Just to clarify, the personal add on that you are referring to is BIS, not. BIS is the personal plan, BES is the corporate plan. You pay extra for both because you are getting more.
Sorry if you don't think it is fair.
And I wouldn't say the iPhone is superior. Different yes. Superior depends on the needs and how it is used.
You still need an iPhone data plan for that, which, last time I looked, cost the same as the one for the BB.
If you want to sell it, visit the Buy/Sell/Trade section. Make sure that you read the yellow sticky at the top and format your post there correctly.