Should I get back together with him?

There is a point when you start to get on your feet that it is important to save almost everything and put it toward the career goal. But if that was the case, he should have been able to say that he knows how much you helped and when he gets through that startup phase, things will be different. Having said that, some guys are terrible at expressing themselves or they don't realize how good they had it until it's too late. If he's at that realization point and is sincere about it, then great (unless you're worried about being hurt twice). But you won't know unless you hear him out.

Tell him nearly these exact words:

If you wanna date him: I will get back together with you but you need to share some more and not be a hog.

If you don't wanna date him: I'm sorry, but I don't wanna go back to you being all greedy and stuff. Sorry.

Wow, that is a tough one. First of all I don't think you should take it personally that he is being tight with his money. Generally someone that is tight with their money has developed that attitude through their lifetime and its hard to break.

Secondly, you should think about what it is exactly you need from him. Do you need money to live/eat/survive, or are you just wanting him to buy you things. If you have the attitude that he should just by you material things as some sort of payback...then the issue might be with you. A strong and meaningful relationship should be based on love, never on money.

The only situation in which you should expect to share his money would be in the case that you are married, as this changes the situation greatly. If it ever gets to that point, you should feel comfortable asking him how you both plan to share the income you both bring in.