Gas prices jump, but not as high, survey finds February 24, 2013 -- Updated 2030 GMT (0430 HKT) Gas prices have jumped 20 cents over the last 2 weeks, according to the Lundberg Survey Prices spiked 54 cents over 9 weeks, the survey found "The chief causes of the rise are out of the picture," the survey publisher says The current national average is $3.80, 10 cents lower than this time last year (CNN) -- Gas prices have jumped again, but there is good news on the horizon, the publisher of a new survey said Sunday. Over the past two weeks, prices at the pump have jumped 20 cents, adding to a total rise of nearly 54 cents over the past nine weeks, according to the Lundberg Survey. A gallon of self-serve regular costs $3.80 on average nationwide, the survey found. But the speed of the spike has slowed substantially. And now, prices may even start to drop, says publisher Trilby Lundberg. "I don't mean that gasoline prices cannot go up further from here," she said Sunday. But the chief causes of the rise are out of the picture. Crude oil prices are now going down, and wholesale prices -- which marketers and retailers pay -- are "starting to tumble," she said. The current average is about a dime over the average last year at this time, Lundberg said. Fact check: Your mileage may vary The survey tabulates prices at thousands of gas stations nationwide. The city with the highest average in the latest survey was Los Angeles, at $4.29. The lowest average was in Billings, Montana, at $3.23. Here are average prices in some other cities: Boston - $3.81 Atlanta - $3.82 Jackson, Mississippi - $3.61 Cleveland - $3.76 Houston - $3.64 Salt Lake City - $3.38 Las Vegas - $3.72 Seattle - $3.75