This is actually a very good product. I owned it for a couple of years. It's not as effective as a stone or a steel, but it's 80% there. The advantage is that it's light, and doesn't break like a stone. It's also good for 2800F like others have mentioned.
Why not use your regular cast iron pans? Sure you can, but your pizzas will be smaller because most people don't have a 14" skillet, and placing the pizza in it is awkward because of the high sides.
I wouldn't pay more than $50 for it though. Lodge screws us royally in Canada. Why? Because they can. I think everyone should stop buying Lodge until they fix their prices.