Welcome to the board. I believe the 3 times materials cost is fair and somewhat accurate to price your quilts.
May I suggest making smaller bundles and then having the expectant parents (and grandparents) have options to add on? Example - basic bundle can be quilt for crib, dust ruffle, bumper pad, and sheets.
Bundle #2 can be coordinating wall quilt, curtains, diaper caddy.
Bundle #3 can be to add on a diaper bag. My thought is that the entire listing will be way too expensive all at once - if you are placing the proper value on your items. I also know that when I have made a Professional Tote (similar to a diaper bag in some regards), it took me at least 9 hours to do.