How fluctuating fuel charges can be captured on purchase order

We have a requirement that, fuel is purchased in different states within USA on regular basis.

For instance it is captured in UOM - GALLONS.

1 Gallon today could be $2.85, tomorrow it would be $3.52.

Every time creating the revision on the PO is very tedious and confusing.

We have explored the Retroactive Pricing functionality, but only when we create a revision the associated PO as getting reflected. but we do not want to create revisions as price on the fuel varies state to state and fluctuates rapidly.