Holy crap that is expensive. I'd expect a service like this to be less expensive than my local home brew store due to the grain bill being ordered in bulk. For comparison, a super high gravity Belgian black will run about $60, including lots of Belgian Candi Syrup. Your average nut brown will run about $20.
$35 for an extract kit, especially something decently hoppy, isn't too bad - especially if your local store isn't MoreBeer or Northern Brewer. (Though I'd feel better about that price if it included Liquid Yeast, and the "extra ingredients") $15 to ship is a killer.
I agree 15 dollars is high but shipping 10 or so pounds is about that much.