After hitting a peak of $3.45 per gallon last week, the national average U.S. gasoline prices are expected to calm down significantly this week due to price cycling, Patrick De Haan, head of petroleum analysis for fuel-savings app GasBuddy, said on Monday. The national average saw over the past week one of its largest weekly jumps in the last year or so, De Haan tweeted on Monday, but added that average gasoline prices should calm down significantly this week. According to GasBuddy, prices are actually down by $0.03 per gallon from the $3.45/gal…