Side and rear windows are a piece of cake to do, but ask advice from somebody who has done theirs first as the instructions I got with mine were, well, shite to say the least.
£50 a roll from halfrauds? I paid £9.99 a roll for mine (enough to do two windows each)
The rear window is an arse to do, but as long as you measure up and cut it into at least 3 strips, it'll come out looking nice. I'm redoing my back windows this weekend to get all the creases out.