Real Numbers
At the location at which I rented last week, Budget was $18 cheaper than the other options. Let's say Budget was $35 and the next least expensive was $53. I drove less than 75 miles.
I rented from Budget, and paid $35 plus the $9.50, for a total of $44.50 + taxes & junk fees.
If I had rented from the other company, it would be $53 rental + about $7 gas to fill it up, for a total of about $60 + taxes & junk fees.
I rented from Budget and saved time and money by not bothering with refueling.
Also, much to my annoyance, Budget Fastbreak is anything but fast. I must go the counter, where they have a sign prominently displayed stating they have a $9.50 refueling charge. They take the time to review the refueling options by asking if I want to buy a full tank upfront, and I tell them I'm driving less than 75 miles so I want the $9.50 option. This causes them to key something in before printing my contract.
Each week, when I return the car, they ask me if I filled it up before printing the receipt. I assume that if I said yes, they might ask for the receipt and not charge the $9.50. Don't know, and am not going to take the time to find out.