Gas prices across Pennsylvania are slightly lower this week than they were last week. That’s according to Triple A, which says the average cost per gallon is down by about two-cents compared to last week, currently at three-dollars and 21-cents per gallon. Prices across the state still remain higher than the national average, which is currently at three-dollars and 13-cents per gallon. Here at home prices are higher still, at three-dollars-39-cents a gallon.