The closet swap always seemed like such a good idea in theory. You grab all the stuff you'll never wear, such as those disastrous purchases, made on a whim, now living rent-free in the back of your walk-in. Your friends do the same, and everybody trades. One girl's trash is another girl's treasure, right? Wrong. Turns out nobody really wanted those lime green leopard-print pedal-pushers. But at the Buffalo Exchange, things are different. The salesmaidens (and misters) know good stuff when they see it, and they're happy to buy it from you. And you're happy to rummage through the well-filtered selections from other emptied Dallas closets. Great finds have been made at the Exchange, from a $30 Betsey Johnson sundress to just $5 for that vintage Alf tee. Would that all other swaps--spit, wives, whatever--were such positive experiences.