Quote a price off the top of my head, no.
I get all information about what the customer wants and write up a detailed estimate, such as time spent designing quilt at $$ per hour, time spent shopping for fabrics at $$ per hour, time spent cutting quilt at $$ per hour, time spent piecing quilt at $$ per hour, time spent quilting quilt at $$ per hour, time spent binding quilt at $$ per hour. I also test all fabrics for bleeding and if there is one, I add in time and costs for soaking/fixing the bleeders. Then I add in all the actual costs of the fabric, backing, batting, and thread.
Most people do not realize how much time is spent on a quilt until they see my estimate. If they want to proceed, I have them sign the estimate and a scope of work with 50% down. The scope of work details exactly what I am making, and what happens to the quilt and their down payment if they don't pay the other 50%.
I've only made and sold one quilt in your size range, and I sold it for $2500.00.