most of the religious people I've known are relatively wealthy
Perhaps you just mostly know wealthy people.
So every possible economic status increases the priors of being religious. Wait, that can't be right.
Increase the priors? Compared to what?
Cannot you just find some real data about it? There must be some, even if not terribly reliable.
The relationships between religion, income, personality and status/politics are too entangled to model. Any intuitive speculation will be worthless. Yet perhaps something could be teased out via data-mining.
This thread on The Atlantic was interested in the connection between red and blue states (American politics), attested religiosity and income.
Stereotypically, people say that religion is the "opiate of the masses", and expect poor people to be religious, because it gives them solace for their problems.
But most of the religious people I've known are relatively wealthy, Mercedes-driving people, to whom Christianity gives the comfort of believing that their wealth is the result of God's plan, and of their own virtue, rather than accident.
And the people in-between rich and poor tend to deviate less from accepted social behavior, and thus are more likely to be religious.
So every possible economic status increases the priors of being religious. Wait, that can't be right.