As Smudger says, without knowing the original price to which your adding your £3 to then its impossible to make a sweeping statement either way. £3 a year on a £40 job, you could probably get away with, £3 on a £30 job you could probably use 10% inflation as a justified excuse this year, two year running might raise eyebrows, £3 on a £20 job two years on the trot and your pushing it, £3 on £10 job two years running and dont be surprised if you lose a lot of work. I've got in laws in Pompey who pay £12 and just had notification it's going upto £15,theyve said nothing but are actively looking for a new shiner, and that's without a price rise last year.