When do you know to leave someone you really love?

My boyfriend and I have been together for several years and we are in love with each other. But, there has been ongoing issues regarding the wide disparity of our incomes and assets which is more important now that we are a few years away from retirement. He wants to marry me and I won't do so because I am really afraid of the financial repercussions. Even to live with him I'm a bit really nervous about if I"m setting myself up for misery.

He works and collects SS so he can pay his regular bills; but for vacations, etc. he needs to dip into his savings which is starting to dwindle away (about $20K left). That's all his has to his name even though he has been much better about budgeting and keeping his bills to a minimum.

I have sought out a lot of advice in regard to this major dilemma. Some folks say love is really hard to find especially at this age and so I should take my chances. Others people tell me I'm looking for trouble and I should just date him forever and never live with or marry him.

Is that the only answer? How do you get yourself to leave someone you really lov? It seems contradictory and wrong to leave someone over $$?