Ok firstly i want to post here, people are asking the same questions and im going to sday something, you are asking about where to purchase cards yeah? you not heard of ebay or something?
Secondly you cannot depend on 1 broadcaster, you need multiple otherwise you will be stuck with the 2 or 3 games on a saturday.
I currently dont use any cards i use an emulator to drive it and i'm just praying that the encryption doesnt change before the start of the season, if it does then i'm screwed basically, if it doesnt change then i'd be very happy.
As for Canal plus i can currently get this service but if you want it legally then you will have to use a subscription card, im not sure if i'm allowed to post links on here due to advertising but anyways here is a list of places you can get cards and cams from:
alsat
hisat
satellite superstore
and of course EBAY or your other auction websites
all you have to do is look, i found these by looking, so theres no need to post the same thing 10 times asking "where can i get a digitalb card"
I googled the terms satellite cards and got hundreds of thousands of hits in seconds.
The price of cards also varies, you can get hold of fake cards if you know the right people but these often tend to only be a few quid cheaper than the real thing, some places have deals, others have offers you just got to take a look.
For people wanting a site for future reference hotukdeals is another good website, it's a link website to sites that have good deals on, i managed to get my dreambox for £98.99 from it which is what i use to receive channels such as premier and c+ using a software cam emulator.
The best receiver for cam's is probably the technomate ones though, simply because they are so simple to use so if you are just starting out id say get a technomate receiver that allows you to insert your own cam into it, probably a 1500ci model or something and then go from there, i dont actually have a technomate but a mate does and it's nowhere near as fiddly as the dreambox is.
Hope ive helped.