How do you decide on key questions regarding sourcing materials like fabric, etc.?

Edit: Should've clarified better, yes she's exploring the business side of it, potentially to sell fabric and custom-cuts.

My wife's getting into quilting. I'm just thinking of ways to support her. Some questions I have:

1. How do you decide between online vs. brick and mortar shopping?
2. What's your selection process in choosing among all potential sellers? Like what are your considerations, e.g. price, etc.?
3. Do you have multiple suppliers for different material needs? Or is one shop usually enough for you?
4. How likely are you to look at other sellers even if you're happy with your current supplier(s)?
5. What are the biggest challenges you face in your typical sourcing process?

Thank you for your insights 🙏