I believe on new subs and on upgrades, Dish charges the first and second months service on the first bill, so everyone is always paying for service in the current month, not last month.
I upgraded from AT120 to AT250 (plus my Stars half price promo ended) and my bill jumped from $87 to $146 because of it being early in the current month's cycle, I was billed prorated for this months and next months service.
Next month after I drop back down, I'll see a substantial credit, otherwise it would drop back to around $110.