I saw this earlier and don't have specific answers, but to help find the answers to your questions, I have some questions. I am not trying to insult your intelligence, just clarifying terms on how quilts are made, and to see what it is that you want. Every different technique can make a difference in how long it would take to make a quilt, and therefore, how much it would cost.
A quilt is typically a certain design of smaller pieces of fabric which are sewn together in the selected design into what is called a quilt top. The underside is typically made from one piece of coordinating fabric. Quilt tops were once made from the scraps of making clothing, sometimes damaged or worn out clothing and other things. The quilt top can be made from one piece of fabric, either a solid color, or a pre-printed design. I have made quilts with pieces sewn together into a design and I have quilted with a piece of fabric that had a printed design.
Quilts can be made by hand sewing through the top, bottom, and batting in between. They can also be machine quilted. Another techniques is to use yarn and to "tie" the quilt top, bottom and batting together.
I once thought I would use old jeans, cut them into 4 inch squares, and design and embroidery something different on each square. I didn't get very far. I can tell you one thing about all that denim: it is heavy! It is heavy to try to sew on a machine. It is difficult to quilt together with a needle and thread. I do have a cousin who does make jean quilts for her sons (3), nephews, and other men in her family.
My questions: Do you want a solid denim quilt, that is just quilted together? This means you would purchase a particular type of denim fabric of your choosing and the person would put the top, batting in the middle, and the bottom together. This would be the quickest and the cheapest as far as labor. Having it machine quilted versus hand quilted would make a big difference. Hand quilting can take a long time. Machine quilting can be finished in one day by someone who has access, but there is a fee for that.
Do you want to select a few pieces of denim and have it cut into pieces and assembled into a particular design? The weight of the fabric will make it difficult for a machine to sew through the layers. Look at the seams of jeans.
If you have someone sew a quilt of fabric that is not cut and pieces, and simply assembled, you are going to get your quilt finished the quickest. But you may have a particular pattern that you would like.