Dont get caught up in the £30 an hour thing, theres lots of people making that, and more.
It's down to you, how hard you leaflet, canvass, the quality of your kit and work, the referrals you get, the distance between houses, how fast you can work at good quality etc etc
For instance i've just started, i'm sure down south a house i quote £10 for, they'd be quoting nearer £15, and probably do it twice as fast, where as up north someone might quote £6 for it, but still do two to my every one so they make more.
Swings and roundabouts really.