Unfortunately, there exists that breed of men who would bank on their education, looks, charm, charisma or whatever else as a short-cut from rags to riches. Having a sweeping criterion, i.e., not to marry anyone with a status lower than yours could be damaging, as you could be ignoring someone genuine. Gold-diggers can be identified easily by hanging out with them to know how much (even subtle) references they make to money. Their track record about money in terms of owing money to friend/family and relying on others for it, could also be a strong indicator.
Without his permission, you can't get his credit info. So, he must agree and get one done on his own and show you the report once it's back.
Another thing sheyn, credit report shouldn't be the deciding factor because he could be going through hard times, student loans, etc. Analyse his work ethic - laziness, will-power. How principled is he - you can tell a man with principles from a mile - how strongly does he stand up for things, etc.
A man with a strong character and principles will not be a goldigger. No doubt about that. :)
Tell them that you'd like to live a very simple life in a middle-class neighborhood. If you were rich or were to strike it rich, mention that you'd take all the extra money and buy an orphanage with it or something. Or spread the wealth around so that you will only be left with enough to live off. Say that you have already done some research into it incase it ever happens. Then see what he says. Of course this is all best to say if you have actually thought of these things so then you wouldnt really be lying. grin