If you take the amount of years it has been since your roof was installed, and divide the cost to purchase and install it by that number, you will get an idea of how good an investment it is. The range of durability is quite great when it comes to roofing, but one material will usually come out on top. Even though clay roofing has a pretty high upfront cost, it can last for a very long time if properly maintained. There are even some that have lasted over a hundred years.
Of course, since a clay roof is so heavy, it does require some care when installing. You should make sure that your existing support can handle the added weight. If not, you might need to install some additional support. Since clay roofing is quite a large investment, you should also make sure that you have a reputable roofing company install it. If not properly installed, the clay tiles could flap in the wind.