Families will be out shopping in full force today, tomorrow and Sunday, taking advantage of the state's tax-free shopping weekend. For three days, sales tax won't be collected on purchases of many clothing items and school supplies priced less than $100, saving shoppers as much as 8.25 cents on each dollar spent, on top of other discounts being offered by merchants.  Over the course of the weekend, the state comptroller's office projects Texans will save $64.8 million in state and local taxes. To accommodate the expected rush, many area malls have extended their hours, with some stores,  staying open as late as midnight. The tax break also applies to online shopping, according to the comptroller's office, including purchases of eligible clothes and school supplies at Amazon.com, which just recently began collecting sales taxes after a prolonged battle with the state.