If you put in a price you are happy with why worry because the wife says is that all? I have priced up many a job when the reply has been is that all, but I am happy with the price and if they are then great everyones happy. Granted the greedy side of me thinks damn I could of made a few quid more here but in reality you will price up tons of work, not get it and think oh, I should of gone in a few quid cheaper. Swings and roundabouts, rough with the smooth however you look at it do the job if you have underpriced have a word with them they might give you some more money or they might not, only one way to find out but dont worry because of the original is that all you will hear that quite a few times if you stick at it but not as often as you missed a bit!