Welcome! A WA trip is an experience of a life time, yet it dose require some good home work and research. And your at a good site to start reading up on it. Even a first timer can have a great trip if prepared properly. But a trip 300km and up past Kal requires a lot more stuff and cash than a trip around nsw or vic. One pub in the middle of no where was more willing to give us a free beer than a glass of water! Ha.
It dose come back what you are wanting from the trip. Generally most grey nomads will caravan park it, and work around a 50km radius of it. So getting out further from that point is probably going to be better. And a lot will avoid the rough roads. 10 days way out and hit town again to replenish is a good way. Ducking back into town all the time makes no sense to fill the fuel tank. You loose it going back. And kills the budget and time. Always calculate and keep enough fuel for a return trip. Kal is the best solution for stocking up on the way up, Rather than lugging excessive supply weight all the way over. Expect to pay $75 for a carton of beer once you pass Kal. $8 for a cold 1.25ltr of cold coke!
Fuel was at fair price this time last year, $1.35-$1.50ltr.
just past the WA border on the left was the cheapest around that crossing. Beware the can be very thorough at the boarder crossing. Sometimes police assisted for illegal guns etc.
if you feel your uncertain of surviving such a trip because of experience and what you need, stick with nsw and vic, and have a practise at camping out for 10 days straight without ducking into the shops, taking note of how much water and food etc you realy needed. Yet still having a shop if really need be. Some over pack, some under pack....
But a trip over there is awsum!