Hi! I work in marketing for Bway shows. Here's the scoop:
Broadway shows sell directly through either Telecharge or Ticketmaster. Any other site is a broker selling tickets - usually at a markup.
You can buy directly from the box office at the theater as well and avoid paying any fees on top of the ticket price.
For discounts, check out Playbill.com, Theatermania.com, Broadway.com and BroadwayBox.com. You can also check out a newsgroup at http://groups.yahoo.com/group/theatercodes/.
For same day discounts, you can go to the TKTS booth. There is one in Times Square and one with almost no line down at South Street Seaport.
More discount coupons are also at the Times Square Visitor Center right across the street from the TKTS booth.
