RIDGEFIELD — In the beginning was the word, and the word was “downsize.” And they saw that it was good.That’s the genesis for the many vendors who have gone forth and multiplied over the past decade at the NW’s Largest Garage Sale & Vintage Sale, a massive gathering of mom-and-pop sellers held thrice a year at the Clark County Event Center at the Fairgrounds.“Too much stuff. We call it `the abyss,’” Susie Lewis of Beaverton, Ore., said.“We just had so much stuff to get rid of,” Diane Sigler of Dallas, Ore., said. She and her husband, Jim, were simply dedicated downsizers of an overcrowded home when they booked a little space at the first experimental garage sale event staged by the Buffum family of Vancouver about a decade ago at the Expo Center in Portland.The experiment was a success at every level. The Siglers “did so well we couldn’t believe it,” Diane said, and so did the Buffums’ fledgling business; today, the sale attracts hundreds of vendors — enough to fill the Event Center and spill over into a neighboring building, too — and the Siglers have four little sales kiosks in curio shops in and around Dallas, where they deal in used furniture and interior decorations.“It’s really developed into a career,” Diane said.Some vendors are in it to make fast cash — for example, the ones flipping the contents of abandoned storage lockers they’ve won at auction. “It means nothing to them personally,” sale founder David Buffum said. But others really get into the hobby, he said, developing savvy about buying and selling, somewhat for profit but mostly for fun.Many are truly fascinated by the familiar-yet-strange stuff they sell. What’s this wooden cylinder with a ring of soft felt at one end and a lid fastened by a leather strap at the other? It’s an antique capsule that would have carried money and forms back and forth between bank customers and tellers in a pneumatic tube — long before plastic replaced elegance with utility.