I don't know if you had a bridal expo or not in your town, but when I went to the one here in Vegas they said to mention "the bridal expo". They say you will get the better discount of $50 off compared to the $40 off coupons they were handing out. Not sure why they weren't handing out those coupons?! I don't know if you could try that trick.
David's Bridal gives out $50 off coupons (at least mine does, just saw the other comment about David's). I got $50 off when I signed up for the email club.