The Arkansas Public Service Commission says natural gas customers in the state will be paying higher prices to heat their homes this winter. Wellhead prices are about 20 percent higher than the forecast last year, and 60 percent to 80 percent of natural gas bills are for the cost of the gas itself. The price of natural gas is determined by the market, which is influenced by availability of supplies, the weather and the economic climate. In Arkansas, utilities don`t mark up the price of the gas; other charges on natural gas bills are for transmission costs. The commission says the montly bill this winter will be a little over 100 dollars, based on using 100 cubic feet. The commission recommends that consumers sign up for the average billing option to avoid being socked with large gas bills in cold months. Under the program, costs are billed through the year on an average basis. ------ The panel also suggests keeping costs down by conserving gas. That can be done by turning down the thermostat at night and when not home for two hours or more. Tuning up furnaces every two years can help efficiency, as can making sure a home is properly insulated. The commission also suggests sealing air leaks where warm air can seep out.