Not having a go at you at all peak but people keep on shouting about standardising the industry including prices so that people are earning a wage that reflects their skill because there are always some that will work for buttons and undercut everyone else. How many thready have we seen on here where someone has been undercut by a stupidly low price and people assume that because the price is cheap the job will be done to a lower
standard and with inferior materials. I think your prices are far too cheap, if you had knocked the £56 off for them that would have been £12.5/m2 or £125 a day and that would work out to about 30k a year but by the time you have taken off your tax, fuel, tools, etc you won't be left with a lot and would probably be earning less than minimum wage.
If you're undercutting slightly to get the job then fair enough but being almost half of what everyone is charging your just going to end up doing a lot of graft for not a lot of money. I would sit down and work out how much you need to earn per day to give you a wage, cover your expenses and holiday pay etc, i would say it will be a fair bit more than you are charging at the minute. Your just ripping yourself off at the minute.
Like i said i'm not having a go at you, if what you charge is enough to cover expenses and give you a wage then more power to you, your in a good position to get a lot of jobs booked in but it is a lot easier to drop your price to get a job than to add money on when its booked in and your prices will follow you on other jobs