Dish will only lease you (at a significant discount over retail purchase price; free for many configurations) receivers to support 4 TVs, and dual-output receivers have both outputs counted whether you use them or not.
Additional receivers must be purchased at retail (and will be owned, not leased), along with any dishes/switches/installation labor to connect them.
Additional receivers must be purchased at retail (and will be owned, not leased), along with any dishes/switches/installation labor to connect them.