The cost to install sky tv is 560 euros and goes down to about 350euros (ish) if you take out your own box and use it as a basic receiver, this is a one off payment and you get all the basic freeview channels - you then have to subscribe to sky as we do here in the uk. I got all this info from Europa TV at the top of the commercial centre in Puerto Rey. apparantly 4 systems can come off one dish.
They also have a system with a mesh dish that costs the same to set up and then you pay 19euros per month for the full sky channels including all the movie channels, the pay sports games but you have to take out an annual contract.
I asked all these questions while we were out there last week and some told us Sky were operating illegally and others told us the mesh set up was dodgey - we will look into it properly when we are ready to go with it.
I am fairly sure my info is accurate but please do not quote me as it is only as good as the people who advised me.