If your wanting Sky + then you will have to pay for the box. (�100?) Also an engineer will have to come out to add an addistional cable to run from the dish to your Sky + box as well (Sky + boxes have 2 cables running in to them, unlike the normal Sky boxes that have just the one)
I can't see how, by already having a dish, you won't have to pay a monthly charge? You'll have to register with them and choose your packages etc, if you didn't have to the people would just arrange for an engineer to put a dish up for them and away they go, free Sky channels......??????