Kad said: "Playwrights Horizon has probably one of the best systems: an under-30 "subscriber" program. It's free to sign up for, and essentially grants early tickets for $25 (I think?) plus guest tickets at a very reduced rate, which you are able to exchange for different dates if need be without hassle. You're essentially treated like a subscriber without having to make a large financial commitment to the season."
Playwrights also has discount codes for incredibly reduced rates for a few early performances if you don't win the Live for 5 lotto, and that's not limited to an age group.
When I see the phrase "the ____ estate", I imagine a vast mansion in the country full of monocled men and high-collared women receiving letters about productions across the country and doing spit-takes at whatever they contain.
-Kad