ps im moving to australia and that is where i will keep my horse
Here in Australia we do it slightly differently to the US and England. While over there "full board" seems to be the norm, many places in Australia, unless you're in the major cities, seem to focus more on DIY horse care. The price is going to vary extremely depending on what you want, where you live and how far you're willing to travel.
This would be my estimates: So a basic DIY (feed, rug, clean yourself) large shared paddock without riding facilities can be had in some places for $20 - $40 a week. In a place with facilities that would go up to $30 - $60. A small shared or private paddock with facilities probably between $50 - $120 depending on location. Many places offer a stable, and with a shared day turnout at that is usually $60 - $150 and these are the costs without food/care.
If you are looking at full care I'd imagine somewhere between $80 - $200 (sometimes more) depending on where you are.
Feed is also more expensive in Australia. I'm not actually sure how much hay is at the moment, but a while ago we were paying $20+ for a small bale of lucerne hay. A feed mix probably $18 - $35. A farrier would be about $30 - $60 for a trim, and $50 - $100 for shoeing. Dentists around $100 - $150.
I'm not going to include the cost of the horse, rugs or tack because while they are expensive they are reasonably straight forward once off costs. It's the upkeep that kills you.
If you tell me where you are planning to move in Australia, people on here may be able to offer better advice.