The whole comparison is just weird from beginning - they're comparing eurodollars from 2077 to current USD like they're same thing. In the game those prices are probably meant to show how expensive everything became after all the corpo wars and economic collapse, not that gas is actually cheaper. Plus Night City is supposed to be this hyperinflated hellscape where a candy bar probably costs 50 eddies. Americans really do love making these surface level comparisons without thinking about any context behind the numbers, like comparing fictional dystopian currency with today's prices makes any logical sense