This article is from the Satellite TV FAQ, by Gary Bourgois firstname.lastname@example.org with numerous contributions by others.
First you need a descrambler. If you get a new system, most likely you
will get an IRD, which comes with the descrambler built in. Just make
sure it WILL upgrade to the VC-II RS, and understand that this upgrade
may cost you additional money when this system is implemented. The
descrambler will add around $400 to the cost of your satellite system.
Next you need a subscription. Movie channels will run you around $7 a
month or so, actually less than cable, but you do get taken for a bit of a
ride on the "generic" cable channels such as DISCOVERY, CNN, etc. You can
not generally by one channel, certainly not at a reasonable cost. Most
subscriptions to the "generic" cable channels (which does not include
premium/movie channels) will cost between $150-$300 a year above and
beyond the cost of the descrambler itself. Some say this is why piracy
has flourished. Piracy is illegal. If caught with a pirate decoder, you
can be fined or jailed. Certainly if you sell such equipment, you can
count on heavy fines, and jail time. Piracy is not good for anyone. Pay
for your subscription, or do like many of us on the net and watch ONLY
programming that is NOT scrambled.