You probably still want to comparison shop with other offers from Bell and competing services. For example, do you still get bundle discounts if you take the receiver rentals? How much do Bell LD and other features cost compared to the competition. If the difference is more than $20 per month on any service, it's not worth it. Also consider that you might be able to buy the 9241 for $300 net and sell it in a couple of years for $200 or more. Even without reselling the receiver, buying still works out to under $20/mo over 2 or 3 years and avoids rental fees or a new receiver purchase at that time.
For installations, the first receiver is free, extra receivers are $50. The extra receivers do not need to be purchased new from Bell. IMHO, the best deal is to purchase a new 9241, take the free installation and pay $50 to install any extra receivers.