All you want is to relax at the spa — but before you know it, you’ve been talked into a pricy body treatment promising you’ll “lose inches” and reserved one of the "limited" weekly thermal passes. But hold on: If you’re not careful, you could find yourself with a spa bill that’s more than the base fare for your inside (or even ocean view) cabin. When it comes to spa treatments at sea, keep it simple and avoid these seven cruise-ship spa rip-offs.