A couple more red flags
1. How much is material cost and how much is labor cost?
2. Give me the material list. I will get the material and that will save you time.
3. What is that chemical and where do you get it?
4. How much can I save if my son helps you?
The answer is "Thank you for your interest in my company helping you with your service needs. I do not think we are a good match for your needs. Good by."