Unfortunately, not all girls are like you! Many girls (and guys!) are very shallow and base affection on money. Fortunately for us broke-ass poor guys, there are exceptions.
Just because a guy can't buy his girl a $1000 diamond ring (or even a $100 one!) doesn't mean he doesn't love that girl as much as a guy who could. Just as long as he finds he own way of showing her, that should be good enough. And if the girl loves him back, he can rest assured that he's found a girl worth dating.