The math of the kit is all broken down on the website.
For the Original size 78x78 you are paying for
Pattern $36.00 (includes templates for applique)
DMC Floss ($3.00?)
18 5/8 yards of fabric (this figure is ridiculous for this size quilt! - but that's what it say's so at $10.00/yd thats $186.50)
for this they are charging $300.