I'm thinking it would be useful for more than pizzas. I'm thinking breads, sourdough buns, flatbreads, as well as anything that might need to go into a high-heat broiler.
I've also got some ideas for using cast iron in conjunction with it. For example I've got two oval-shaped, fajita-type cast iron skillets -- I can see using those for sizzling fajita ingredients.
As for the cost, I get a pretty decent discount because I work for one of the retail chains that sells them.