There’s nothing simple about back-to-school shopping; between the materials fees and clothing demands, budgets can be pushed to the limit. Denver-area moms have these tips. Virtual yard-sale groups. Johnstown mom Christine Miles purchases a couple of new outfits for her kids at the beginning of the school year but generally tries to shop year-round at garage sales and thrift stores. “I have recently joined some virtual yard-sale groups on Facebook, and I love them! It’s faster than going to a bunch of different sales and by joining or starting a group in your area, it’s really easy to buy and sell. I quickly sold my car because I responded to someone saying they were looking for one.” Clothing allowance. Now that Lisa Cutter’s kids are 12 and 13, she giv...