If you are buying some fast food or a small item at a convenience store, you may notice that the cost is a penny or two higher than it was the last time you bought it. That’s because the sales tax has just increased. On April 1, which was Saturday, the county-wide eighth-of-a-cent library tax kicked in, and so did the three-eighths-of-a-cent tax in Nevada County that is being used to keep the fire station open, and to hire another police officer. Added to the other local sales taxes, residents in unincorporated Nevada County are now paying seven-and-a-half percent in sales taxes. It’s an even eight percent in Grass Valley, and eight-and-a-half percent in Nevada City. The statewide sales tax, without the local taxes added on, is seven-and-a quarter percent.