Totally depends on the individuals involved. Everyone's criteria for a marriage partner is different. I know plenty of people who have married poor people with low status jobs as those things were not important to them. I also know plenty of people that would never date/marry someone poor with low status because that's not the type of person they're attracted to.
As for economical marriages working out.. they could. If he wants something she brings to the table (looks, personality, sex, child raising abilities.. whatever) and she wants to be associated with his status as a doctor and have his money to spend and both parties are perfectly clear on what their relationship arrangement is, well, it could work out just perfectly for both of them.
_________________
Just because you don't believe me doesn't make me a liar.