The roads of these mountain towns were encrusted with homemade, hand-painted signs, many in Day-Glo paints for tag sales, garage sales, yard sales… that was only five years ago. The listings for these sales expanded to more than a two-page spread in the local Shoppers’ Guide.  Then came the pandemic, which increased the use of online marketplaces such as Facebook Marketplace, Craigslist and eBay local pickup.   On weekends these days, the roads are dotted with signs for tag sales and towns including the Empire State’s Hillsdale, Germantown and Valatie have organized town-wide tag sale days and flea markets. Forty-five…