In looking for a cheap, easy to sew quilt design, I came up with the following idea. Take one long piece of cheap ripstop 2nds, twice and long as your quilt will be, plus add four inches for each baffle. On the "bottom" side fold over at each baffle interval (say every seven inches) to create a 2 inch baffle and stitch. Then fold the "top" side over and sew each baffle to complete each chamber. Finish as usual.
I'm sure this has been done/discussed before, but if it's been on this forum I couldn't find it. Also, I know this is doubling the material (and thus weight) for each baffle, but lets try and forgive those few grams for the sake of simplicity. Any thoughts? The only down side (no pun intended) I could come up with was the direction of stress on each outer seam would be more likely to open and create holes for down leakage, but I'm unaware of how big a difference that would be.