What to say when the contractor says "we can't do that"
"We can't do that" is almost never final. It means one of three things: not possible, not something we do, or more work than they'd like. One question tells you which, and each one has a different next step.
How to read three contractor quotes when your list isn't on any of them
Three quotes are almost never for the same job. Put each one next to your list of what the house has to do, mark every line priced, missing or unclear, and the question changes from "is this expensive" to "is this quote for the project I asked for."