Bills advancing through the legislature would exempt groceries and medical services from the Hawaii general excise tax.  Hawaii is one of the few states to tax groceries.  Supporters, like the Grassroot Institute of Hawaii, say a family of four in Hawaii spends an average $1,000 a month on groceries. That's twice the national average.  Cutting the state tax would save a family $450 a year.  Lawmakers are also considering another bill which would double the tax credits the state offers to renters who make less than $30,000 a year.