I don't have any numbers but I do have a few things that I'd ask myself if I was in your position. It's obvious that you are going to Statecraft so you are paying the full faith cost for those buildings. Let's also not forget that you will need another Great Prophet to enhance your religion. How long will it take for you to get your two faith buildings up in all of your cities?
In addition, you are probably going to plan spreading your religion so are you going to rely on pressure alone? If not, you will need missionaries and they cost additional faith. The good thing about the yields is that you will be spreading your religion as quickly as possible to reform sooner so you get the benefit in the process as your religion gets to your cities. If you are aiming for the really late game, then this can work (though whether Mosques will remain available is another question).
For me, I like a faith building if I have immediate religious competition. Otherwise, the yields, at least the good ones, go very quickly and grabbing them after getting a building is less likely. Of course, I'm also someone who doesn't always get religion so what do I know.