brdwybound04 - Well Friday - Sat evenings are probably the most sold on broadway - followed by Sunday matinees. So it really is going to depend on what kind of a weekend it is and what the ticket inventory is like by then. Like I said, I scored front row seats (off the hudson Theatre website) the day before. But, that being said, that will be near the end of the run for Sunday, and the Hudson is a small theatre so if you have your heart set on wanting to see it, I wouldn't advise waiting and hoping to score better priced tix.
If it was something else (i.e., my other favorite on Broadway right now - Sunset Blvd) - with a mamoth theatre, and a run going till the end of June, you could definitely wait and would end up finding something a bit discounted... but with Sunday that is quite a gamble that I'm doubtful you'd be successful at.
Not to make this more difficult for you, especially if finances make it prohibitive - I would not miss Sunday if you can help it. I treated myself that Saturday afternoon I went to see it and am still thrilled that I did (and have been trying to see if I could swing a return visit)