you're getting ripped off, mine is $41 for 10Mb which i thought was bad enough (cap is about 5GB a day between 4pm & 11pm, even then all they do is reduce your speed if you go over, rather then charge. rest of the day unlimited).
least its cable, so stays at 10Mb all the time
unlike adsl which i've had in the past. which always gave me a massive range of speed