Quote from @Svetlana Kazantseva:
Hi all! We have a really hard time finding a general contractor for our repair project in a buy & hold SFH in Kansas City, MO. We hired a property manager after purchasing the house and both contractors they sent in are "skeptical about providing a quote if they cannot use their own materials". In their experience "it has lead to a lot of headaches and delays with the project". We are out of state investors and were going to stick to David Green's advise of getting quotes without the materials for fair comparison + being able to select the material we want, put it on our credit cards. Do you think it's reasonable for contractors to refuse a quote without materials? Should we keep looking?
This one lit a fire!
I can say I've done both. The deciding factor has been the size of the project.
For example when i had rooms and a recording studio built, I did NOT buy materials. The contractors did. You don't even want to get involved in trying to shop for everything they need.
When its something smaller, like installing tile floor, doors, blinds, light fixtures, etc. I've provided the materials. These are usually a handy man, or small time contractor job, like a contractor that regularly does turnovers for vacant dwellings and some rehab is needed.
Once you get structural, involve utilities, or it's a very big job, you can appreciate why you need to let the GC get the materials themselves. You don't know enough to buy what they need, it's inefficient for them to wait on you and your schedule, if you get the wrong thing or wrong size it costs everyone money and slows things down.