You are going to have to contact individual farriers in your area and inquire as to their rates -- there is no way for anyone here to tell you what the ones available to you will charge.
As an example of how much it can vary - for trims only on two horses the four farriers closest within my immediate area range anywhere from $50-120 per visit.
If you are in a boarding situation or have "horsey" neighbors you can often schedule things in a way that you can split the farm call fee to reduce everyone's individual cost. The farm call fee is genearlly minimal enough, imo, to make the hassle of hauling your horse in not worth the savings.
My trimmer does charge more for pushy horses, unhandled horses, and she won't do drafts unless they're really really good (apparently, in my area, the drafts she's done have terribly behaved as a whole).
We have quite a few members here from Oz, hopefully they'll chime in for you.
As others have said, they vary quite a bit. Around here they range from $25 - $55 for trims. Mine charges $45 unless you have quite a few and then he gives a multiple discount and no trip charge. I pay $35 per as I have enough horses to fill up a whole day's schedule for him.