Prosperity gospel? That might sell well among the poor. I don’t mean it’s insincere, even though the theology is plain wrong.
Marvin Winan and his sister probably made most of that kind of money with their hit-gospel songs and concerts of the 80’s and 90’s where they had record success. I haven’t heard anything of Winan involved in anything scrupulous with his teachings or dealings so if he made that money legitimately because people bought his records then I don’t see the problem other than him flashing it as a pastor