I usually get at least 3 quotes. A detailed quote is a good sign they know what they are doing. An open ended quote is a good sign they dont. This does not work 100% of the time. But a good diagnosis goes a long way. Someone I know wanted a bit of electrical and sheetrock work done in their house. The dude gave her a piece of paper with 1 number on it, how much. No detail/swag of material, no detail/swag of hours, nothing, just a price. What is interesting is I (and this is just luck) I seem to always get one awful, one medium, and one good. Just kind of worked out that way. The nice thing is once you find a decent contractor they can recommend others or do the work themselves. But finding a decent one can be a pain.
Getting quotes will help you if you already knew exactly what work you needed performed, but if I had talked to 3 water infiltration mitigation companies I would have just ended up with 3 quotes in the tens of thousands of dollar range. None of them did landscaping, which was what I actually needed. So I wouldn't rely on quotes when there's any ambiguity in the problem. I would rely on quotes if e.g. I needed to replace my entire roof, or replace all my windows. Those at least are narrowly scoped.
