i really suspect the issues are to do with incompatibility and/or communication issues not the financial disparity.
i have friends, date people who are way different to me in terms of disposable income etc.
sometimes the guy has had a couple more noughts than me at the end of his income, sometimes i've been breadwinner.
the money itself isn't the issue: it's more attitudes, compatibility.
ideally in caring friendships/dating BOTH parties should be out to make the other as comfortable as they can - i don't mean "give me all yer cash" but reading what makes the other most at ease whilst doing things one likes.
i also think sometimes people can be fairly passive-aggressive where money is concerned? i have some poor(er) friends who will actively suggest nice stuff to do within their income (i do the same myself as I'm a bit skint - walks or art or whatever is all free!)
then again, there are some who will pull faces when the bill comes and do a poor me/alright for some attitude, thus ruining the night for everyone else/their date?
why not just own the social situation, say "this isn't within my budget" when it's organised and suggest a cheaper activity/place rather than using it as an opportunity to play the martyr?