I’ve done over 50 renovations and my approach with contractors is to get at least 3 very detailed quotes from them. Especially important is breaking down the labor vs. the actual materials.
I’d do a bit of extra work as I’d supply them with an excel spreadsheet to fill in the cost for each thing in each room. That way I could easily see where the differences were.
And then it’s just a matter of them either agreeing to go lower or match another quote or not.
It was a really educational experience for me as many times, contractor A would show me how they were able to get it down or explain it was impossible, etc.
Some contractors are busier than others and value their time more. But the key is just seeing where the differences are and seeing if they will agree to match it.
It’s been my experience, if you’re really cool with them and not a jerk about it, most will match others if it’s truly and apples to apples comparison of the quotes/materials.