What does it mean when a guy keeps on mentioning he is broke?

Only way to find out why he mentions this is to also lets us know the details as to when/why he is mentioning this. As the other poster said, many reasons to say this excuse.
Testing you out to see if you're a gold digger
letting you know that he is broke so that you don't think sure going out with a rich guy
giving you the hint he won't be paying for dates and he wants to go dutch
giving you the hint that he doesn't want to go out and do fancy activities
anyway, those are a few common reasons. Would be interesting to know as to when he is bringing up this subject though.

It depends on how he follows up on his claim of being broke. If he suggests that the two of you go out for drinks or dinner or some other activity that requires spending money, then he's most likely a mooch, and will try and take you for all you're worth. But if he just casually mentions it, and suggests a low-key, evening or date, then he might just be being honest.

He sure can. The three main reasons why he does that are
1) He is insecure about what you'll think of him once you know that he is broke. So hinting it early on serves as a cushion or weasler.

2) He wants to come out clean and just let you know his current situation

3) He could be testing you to see if you are a gold digger or not

As for you or other ladies, do you mind if the guy does not have much money?

1. He probably not interested in you and he think that if you know that he is broke then you would just forget him.

2. Maybe he does like you. And he just wan to see if you would still like him wen he is broke