I just moved to a new house and as part of that I built a full outdoor kitchen, my dream. So its tough to specifically say how much it cost.
What I will say, even if it cost 2x what I paid, it is worth it. The pizza is awesome, and its alot easier to learn than I thought. Especially with amazing resources like this community. People who come to my house and eat pizza are amazed. I just recently catered my Mother-in-lars 65th B-day with it too.
I learned everything I needed about building a fire from reading stuff here/oven sites, and putting that into practice during the 4 day curing process (I have a Mugnani).
I was worried in practice it might get a bit tedious, or not be as much fun as I'd hoped. Well, those worries were just silly. Its a blast, and the whole family enjoys it.