Sometimes, you get the idiots that think the price is negotiable after it's finished. In some cases you can lower the bill a bit if the job went faster than you expected but when you work by the hour or the customer wants a price before you start, that should be the price. The customers attitude has a lot to do with it. I went out to do an estimate for rototilling, levelling and sodding a new home with a large lot. It was about an hour away from where I lived. Went out gave an estimate to the guy's wife based on what they wanted done. 2 days later the guy calls me and asks when I'm coming to do the estimate. I said I did 2 days ago and he says he has some changes so I go back out and give another estimate, $1200. Then after I get the job he changes his mind again 1/2 way through and wants a smaller garden and sod beside the house where originally he wanted to put a flower bed. I said no problem but it's going to need more sod. I said I'll charge you for the extra sod (5 pallets, about $250 if I recall) but won't charge for the labour to install it. I thought that was more than fair. He said yeah, go ahead and get more sod. Then when the job is done he gives me a cheque for $1100 and said he's holding back $100 incase there's any problems with the job. He had the city lot grading inspector out 3 times checking my work and the guy who is extremely picky said it was perfect, no problems before the sod was laid.
I wasn't having any of his BS so paid $25 and sent him a statement of claim. He calls me and wants me come and look at the job and clear up the bill. I go back out and he says come in the back yard. He walks around for a few minutes and then says look at this, he steps on a piece of sod and then steps on another piece. See it's lower. One piece of sod was, I kid you not, a 1/4" lower than the piece beside it! I said nobody guarantee's sod will be exactly the same width and you haven't even cut it yet. Once the seams grow together and you cut it, it will be even. Then he says I wasn't even the lowest bid, I was the middle bid. I told him I used premium sod and all he had to do was look at his yard and compare it with other yards. He agreed it did look better. He had the greenest yard in the whole neighborhood. I got a good deal on the sod because the owners of the sod farm were long time customers of my dad and good friends of ours. They use only certified seed and they guaranteed it. It was cut in the morning and delivered the same day. It was the same sod used in Commonwealth Stadium and on major golf courses.