Wedding website TheKnot.com recommends that a bride spend 10 percent of her total Big Day budget on her dress. By that measure, a $20,000 wedding would call for a $2,000 dress - ouch. Bridezillas on TLC's cringe-inducing show, ''Say Yes to the Dress,'' routinely plunk down thousands for designer ball gowns at New York salon Kleinfeld. And the breathtaking