Buying the equipment may get you out of a two year commitment. You MIGHT be able to sell it later- at which time it will likely be outdated and of little resale value. And tales abound about Dish claiming owned equipment is actually leased.
The ONE reason (IMHO) to consider owning is that you can start and stop service at any time. For example, when/if I move to Hopper, I will likely have Dish install 2 Hoppers With Sling & 2 owned Joeys. Then I can activate 1 or 2 Joeys, and pay for service, only when we have guests.
I'm only an operation and a job and a little prep work away from doing that!