So some prices from our just completed trip:
If you are travelling up the Stuart Hwy, Marla was $1.91 pl. Kulgera and Erldunda are similar.
Yulara was $2.21
Kings Creek Station was $2.38 (stayed there but didn't refuel - highly recommend the campsite)
Kings Canyon Resort was $2.32, you can also buy your Mereenie Loop pass from the servo, $5.50.
Hermannsburg was $2.20
Alice Springs was $1.78
Didn't fuel up at Curtin Springs, but a slab of VB was $88

Half a dozen Beam cans was..........wait for it........
$55

Supplies were dangerously low at Yulara, and only one place does take away grog, and you have to be staying at Yulara to buy it. Then they only sell beer by the six pack.......$25. Equates to $100 for a slab. Ouch!
So make sure you stock up on enough grog to last you in Alice Springs (and yes, I savoured every single drop of that $88 slab!)

Matt