So you add up the materials cost, materials mark up, overheads, labour, profit margin, and that's the quote. Yes? No, that's not really how it's done.
That method would apply for true competitive tendering perhaps. But even then not always.
I've spent a lifetime observing tradesmen and talking to them and the way many do it is like this.
The tradesman first of all tots up the materials cost and the time the job is likely to take. He can do this in seconds. Between parking the van and knocking on the door he can work that out. That's his base price. He then considers the following. What's the going rate for the job in the area. What do all his mates charge? How far upwards can the price be pushed above the base price? How busy is he? What's the customer like? Is he a softy? Is he naive? Is he a push over? If he seems a bit awkward or fussy and big for his boots, then give him a f*ck-off price. If he's one of them that wants to show the missus how big and bold he is by bullying tradesmen (these are usually short blokes) then give him a serious f*ck-off price. If he's from an ethnic minority and starts to barter and be a general pest then make an excuse an leave. What's the chance of the job expanding from a small unprofitable one to a big profitable one? How much hassle is it going to be parking the van right outside the house? Is it an area where leaving the van unattended is a risk? If it's an outdoor job, what's the weather forecast?
Bill