Thats what I've seen on some. Usually it's ridiculously small download limits so if you like downloading music or films its useless.
Another one was offering access but limited to off-peak times. If you wanted to use it during the day the price doubled!
For example Tiscali seem good, but their 1Mbps at £15.99 ( the same price as 512Mbps) only allows 2GB a month! You'd need to pay £20pm to get their 15GB limit.