If you are talking about S tile similar to Eagle or Eagle lite, the cost is approximately $425.00 per square. A square is 100 square feet if you are not aware of the term. So, generically, about $4.25 a square foot depending on the condition of your existing sub structure. The biggest concern with clay or concrete roofing products is the weight. Do you have tile or concrete now? If you do not, your home may not be engineered to support this type of roofing. Have a look in your attic, if you have standard 2x4 roof trusses I would not recommend these types of roofing as they are too heavy and will cause roof sagging.