There are definitely way too many people (men and women) who are just after money. One of the downsides of being rich is that those kind of people tend to sniff you out and come after whatever they can leech off of you.
Being poor, I don't have that problem. If someone likes me, I can be pretty sure they're not after my money.. because I don't have any.
That said, with or without money, relationships can start out good and turn sour for many reasons completely unrelated to money. When relationships start, we're often putting on our best face, and the people we're dating only see the positive side of us (and we of them). After a while, unless we have outstanding acting ability (and usually some kind of pathology which keeps us from being genuine with our loved ones), we start to show our true selves to each other.. and we (or they) might not like what we see.
That's when relationships can easily fall apart -- especially if both people aren't mature enough to recognize that most relationships require hard work to keep them going in the long run, and aren't committed to doing that work. Communication is especially important at this stage.
What am I doing wrong? How can I do better? What do I want out of this relationship? At a fundamental level, are we really compatible?
These are questions we have to ask ourselves and each other, but most people are really bad at communicating -- especially with people close to themselves, with people who they feel vulnerable to and who they don't want to hurt.... until they can't take it anymore and things blow up.. but by then it's usually too late to make amends.
So, yeah, if things are going wrong for you over and over, and if you or the people you're dating are falling in to recognizable patterns, you might want to start by asking yourself some tough questions.. perhaps with the help of a good therapist. Negative relationship patterns are one of the things a good therapist could really help you to break out of -- in more constructive ways than just giving up.