I cant quote you actual prices because its a couple of years since I crossed but some advice which I received that was very helpful, prior to leaving Ceduna check at the Tourist office and see which way the wind is blowing if you get a tail wind will save heaps of fuel.
Do Not stock up with heaps of fresh veg and fruit at Ceduna as you will have to dump it a few Klm down the Road.

Reasonable Fuel price at Eucla and most other stops across to Noresman are fairly expensive and don't by fuel at the Big servo on highway at Noresman drive into town usually cheaper by several cpl

Hope this helps a bit and have a great trip there is plenty to see on the way over.