I looked at this route recently since I want to make a quilt as well. JAF is not a good source, the synthetic insulation is heavier, bulkier, and more expensive than Climashield. My skills at sewing do not allow for a down product, so I went with 3.6 oz/yd CS.

Searched may places, the least expensive I found was by sourcing everything from Ripstop by the Roll. Going cheap I could make it for $43.55 (less if you want to use end-of-roll, but they didn't have any colors I cared much for), I went for Taffeta as a lighter material, thought a good deal more expensive, topping out at $69.70 for everything.
Life should not be a journey to the grave with the intent of arriving safely in a well preserved body, but to skid in broadside, thoroughly used up, worn out, and loudly proclaiming Wow! What a Ride!