another thing that many miss, just because you are VAT registered doesn't mean you are 20% more expensive than those who are not. your only 20% more expensive on your labour only. all the materials you've bought, fuel etc all has had VAT paid, which you (and customer if they were VAT registered) cannot claim back
so, lets say you have a job and you are charing £40. materials cost £50 + VAT. fuel to get to the job was £10+ VAT (obviously alot more costs involved, but again, VAT would be paid on them either way)
not VAT registered will cost £112
VAT registered will cost £100 + VAT, £120. not really all that much difference...