Ok I'm in the middle of an argument with someone about this so I figured let me ask a bunch of people rather than a single person. Last Friday I went out and gave an ESTIMATE to repair a lawn sprinkler system on this house. Now I assumed that there were no more than 4 zones there judging by the size of the property. I estimated that the job was about $570 parts and labor. So I start the job today only to find out there are 5 more zones. You see the amount of water available is horrible therefore you can only put so many heads on one zone. SO I called up there person in charge of th e house (the Realtor) and told here that the job would be a lot more than what I said because of the fact there are more things to do. I came up with an estimate of $1000 to do everything and I told her ON THE PHONE this is not including today. OK long story short, am I double billing this person for the job, and should I only charge them 150 now and 850 later?