i never tell prices of the materials there are too many determining factors as the cost of materials, example your interlock costs you $4 per sq ft your gravel costs $7.5 per ton how deep is your gravel your geo text cost so much per sq ft your sand is so much per ton you edging is so much per piece the spikes for the edging the trucking to get all the crap out the cost of the machine you use to dig with putting this on a quote will scare a customer into thinking it is much more then it is. follow the kiss method, keep it simple stupid! and so on when your customer looks at the price of the materials they see only the cost of the block the rest of it is a black hole to them, i have only quoted a job with break down once, they loved the inital price but after break down had someone else do the job because they didn't like how much they seen in the labour column. everybody prices differently. As for the original poster, you quote a 30 skid job, don't worry about the $1000 in loss, but i would sure as hell make my supplier pay for it if they gave me the price for it. as a matter of fact i have made my supplier give me materials in situations like that. they mess up not me, therefor they are paying for it not me. If i screwed it up then i just go on with my day, they screw it up thats on them to fix the problem.