Wedding Brunch for 40 - $20/head?
First of all, congrats on a wedding!
Secondly, try The Sunburnt Cow (in the ABC parts of the East Village) or its sister restaurant Bondi Road (more LES, a block away from Economy Candy!). They have all you can drink weekend brunch special for $15 (before tax and tip). Nothing fancy in terms of what is included in the brunch menu but I love the drinks, food and the waitstaff!! (a very attentive, sweet, cute and darling bunch.)
You should call the owner (Heath is the name I think) and ask him about it. The only caveat is that for a large party, ALL MUST BE PRESENT before they will seat you guys. But since you're doing a wedding brunch, put more money down and secure the spot, and make everybody show up on time.