When i first started i found a few posts stating things like, try charging 'X', 'Dont charge what others charge etc'
I didnt take this on board for probably the first 2/3 houses, then i tried it, from a £9 house, i charged the same house at £11 or £12, got denied the first time, but after that it was plain sailing.
Lets say you do a minimum of ten houses a day, thats an extra £20-30, £400-600 a month!
I'm a newbie, so dont take anything i say to seriously, but most people should be hitting £130-£150 or beyond, i do that in a fairly underpriced round, but compact, and a well priced round, but spread out, so it can be done in most areas.
Just my 2p worth (although i wouldnt pay for it!)