Diners eat on the front patio of Dylan’s Barbecue Saloon on Northwest Highway in Dallas. (Photo ©Chris Wilkins/Texas BBQ Posse) Eating good barbecue for lunch in Dallas can often be a costly proposition, sometimes heading north of $20 at the better-known joints. The Posse is always on the lookout for the next great lunch deal and we recently found one at Dylan’s Barbecue Saloon, located just west of Loop 12 on Northwest Highway. Dylan’s was opened a little more than two years ago by Dylan Johnson, owner of Milo’s Bar in Arlington, in partnership with long-time caterer Bryan Mahoney. I…