Depending on how long you will be working for these people would make a difference, if its long term check out with other people in your area that do a similar job use yellow pages for this explain to them what your doing and ask them if they would not mind giving you an idea of what they charge for this work. If you don't have any joy with that just ask them what do you charge on a daily rate for plaster work etc.
As for short term it may be best to leave it for now, but the next job work your price to about £100 a day if this works and there happy with your work then try £110 a day next time. depending on the amount of work you will depend on the price you charge. If your not getting work then reduce your price.
Earning more more money is all about speed and quality, if you do a job for a price and it take less time then you first thought then you make more per day. But beware it can work against you and take longer so you earn less.
As for skill level it does count but demand for labour increases costs so even if you you are just a good DIYer you can still do well money wise.
As for short term it may be best to leave it for now, but the next job work your price to about £100 a day if this works and there happy with your work then try £110 a day next time. depending on the amount of work you will depend on the price you charge. If your not getting work then reduce your price.
Earning more more money is all about speed and quality, if you do a job for a price and it take less time then you first thought then you make more per day. But beware it can work against you and take longer so you earn less.
As for skill level it does count but demand for labour increases costs so even if you you are just a good DIYer you can still do well money wise.
