While retail gasoline prices have soared in California, prices at Texas pumps have hardly budged. The weekly AAA Texas Weekend Gas Watch released Thursday shows regular unleaded gasoline is averaging $3.55 per gallon, just a penny more than last week. That's at a time when the national average climbed 3 cents to $3.81 per gallon as refinery problems fueled a 50-cent increase in California's average gasoline price to $4.67 per gallon. The cheapest gasoline in Texas this week is found in Galveston, where the average price fell a penny to $3.50. The most expensive remains in Amarillo, where the average price remained unchanged at $3.60.