The US gasoline distribution system is fairly efficient in spite of people complaining about federal highway tax and local taxes. (Compared to the retail gasoline prices in Europe and Asia)
The CME crude oil futures, with WTI and Brent averaged, are about $122/barrel, or $2.90/gallon. For oil, 1 barrel = 42 gallons.
RBOB (wholesale, unblended) gasoline futures are $3.61/gallon. So, There is only $0.71/gallon for global shipping/refining costs. Generally, RBOB/unblended gasoline is distributed regionally to avoid damage to pipelines, storage tanks and tankers (railroads, trucks).
Then there are local blending (much of it per tanker truck), distribution and retail pump costs, plus local taxes. Retail gasoline costs are $4.00-4.75/gallon in the Midwest & East, $5.00-6.00 in the West. This is still very efficient pricing considering that $2.90/gallon is just from crude oil prices.
Keep this mind as crude oil prices jump around a lot, and some are saying that soon, crude oil prices may be $150 or $200 or even $300. It is fair to assume that incremental costs beyond crude prices won't jump around as much.https://www.cmegroup.com/https://www.gasbuddy.com/gaspricemap?lat=38.822395&lng=-96.591588&z=4