No problem, since that thread is about one member here wanting advice about a specific upgrade from a 722K to a Hopper With Sling. This thread is a good place for more general questions, so thanks for posting.
Starting one month from now, the Hopper fee would be $5 for a purchased Hopper 3, and each purchased Joey would also be $5.
The main advantage would be the new lower equipment fees. The ability to deactivate and reactivate the receivers whenever you want, without having to return them to Dish, is also a very nice bonus. And of course, when you are done using the purchased receivers, you can resell them to get some of your money back.
Plenty of other places sell Dish equipment. Solid Signal seems to have a good price on an upside-down Hopper 3.
Just hook up the purchased receiver, and call Dish to activate it. Then, they can deactivate your leased equipment, and send you a box with a return shipping label. There is no need to get prior approval. However, if you are purchasing a used receiver, it is a good idea to get the Receiver number and Smart Card number for that receiver, and check with Dish before buying it. That way, you can make sure that it actually is a purchased receiver, and that there is no past due balance on its previous account. Leased receivers cannot be transferred to another account, they must be returned to Dish. If there is a past-due balance on a purchased receiver, that balance would need to be paid off before the receiver can be activated on another account.
I do not make any recommendations on where the best place is to purchase a receiver, so it is best to shop around for the lowest price.