5000 Gold... Your equation just isn't right. So you want to convert 500 pop after late medieval/renaissance, when all main players have their religion everywhere in their empire already? How much Faith do you have to spend? What will you even convert without conquering it beforehand, effectively just turning the gold into a tiny bonus? There might be a few CSs alone on a continent or islands separated, but let's generously assume that's 50 pop, so 500 Gold If you can already conquer everything with confidence, 5000 Gold is a pittance over such a long period of time when you have to spend tons of Faith to get there, Faith that could be spent on something else. If you want to conquer other continent stuff, you have to use Inquisitor + Missionary, and the benefit might just as well be considered part of a post-conquest gain.