Texas shoppers can save money on back-to-school purchases this weekend as the state’s annual tax-free weekend gets underway Friday. Through Sunday, most clothing, footwear, school supplies and backpacks priced under $100 can be purchased without paying state or local sales tax. Online purchases also qualify, provided the order is placed during the tax-free weekend and meets the eligibility requirements. The Texas Comptroller’s Office estimates shoppers will save about $143 million in state and local sales taxes during the three-day event. Tax-free weekend runs through Sunday.