Home prices are a bit like a pressure cooker, to stop the pressure all you have to do it take the lid off! Certainly farmland is valuable, just like air! To suggest that there is a shortage is obviously wrong!
Take a look at a google map of South Australia. You will see that urban land is a very small percentage. Add to this the fact that we export billions of dollars worth of food each year. Making land available for 100,000 people would only take 77km2 *. That's less than 0.02% of the agricultural land in SA
The ABS predicts all of South Australia won't have 1.73 million till 2016!
*At a density of 1295 people/km2 (which includes room for roads, industry, houses, hospitals etc)
Source: ABS
So 100,000 people @ 1295/km2
= 77km2 = a block 9km x 9km
*Total SA landmass = 983,482 km2
*Total SA agricultural land = 500,646 km2 (approx in 2006)
Source: ABS 1345.4 - SA Stats, Aug 2008
*77km2 divided by 500,646 km2 = ~0.02%