Hardwood floor is standard for the den all the time from the beginning. For the great room, the area is not that big so the upgrade is roughly $5000. All the areas in light grey on the floorplan comes with ceramic, and they are not considered as part of the great room. For example, the great room for Devon model has an area of 15' x 13'8".
So the point is, the current promotion only adds hardwood to the great room, which happened at least once when RR was officially launched. If you look at the details carefully, you'll notice that Uniform actually gives you better run for the money. For the hardwood floor alone, Uniform gives on-site finish hardwood floor in living, dining, great room and kitchen, whereas Cardel gives less expensive engineering floor in the den and great room (only with promotion). If you want to match all the stuff Uniform gives, you'll find Cardel is a much more expensive house to buy.