I found my first Schlemmertopf at a yard sale, never used and with instructions. Ten years later I own 6 different sizes including some Romertopf brands. I don't use anything else for baking, ever, with the exception being obvious things like pizzas or cookies. So far I have found many of mine second-hand; I believe this is because people don't use the bakers properly and think they don't work.
Let me be clear on this: you need to read the instructions. I'm not used to doing that, so I'm very grateful I did this time. You MUST soak the baker in water before using for the first several times. The terra cotta absorbs the water and then diffuses it inside the baker during cooking. This creates a moist atmosphere and a naturally-occurring broth for meats. After it becomes seasoned with regular use, you rarely or never have to soak it again. Soap, cleaners or the dishwasher must never be used as the terra cotta absorbs the "flavor" of soap and this will ruin your food, however they clean up really well with water. The bakers turn out perfect, moist roasts, meatloafs (no need for a special meatloaf pan!) and chickens and food generally cooks in less time. The coloring of the bakers will change with use, just chalk it up to part of the charm of using "real" cookware.
Whenever I am cooking for company, they ask about the bakers - apparently few people have seen them or know anything about them. For that reason, they make great gifts for people who love to (or simply have to) cook.