If the prices are under £10 then assume an agency; paying min wage and client supplied materials.
I started at 12.75 (all materials, liability AND fidelity bonded) per hour....
I now charge 14.50....more work than I can cope with (even with 3 more staff), still recruiting and turning work away (ouch!)
I dont care what those around me charge, I really couldnt care less. We spend 8 weeks training staff, provide uniforms, signwritten cars, pay above minimum wage and guarantee the service. We always get fantastic feedback and only lost 1 client when they changed jobs.
Offer a good service, invest in your staff and believe in yourself.