The high-end Android phones start out roughly the same price as the iPhone, but drop quicker (because new high end models replace them quicker).
Here are the Australian unlocked prices (Android reseller chosen because it was the top result in Google):
iPhone4, prices $719-$999: http://store.apple.com/au/browse/home/shop_iphone/family/iph...
Samsung Galaxy S2, price $749: http://www.mobicity.com.au/samsung-galaxy-s2.html
Samsung Galaxy S (ie, old model similar age to iPhone4, which started out priced similar to iPhone 4), price $549: http://www.mobicity.com.au/samsung-i9000-galaxy-s-8gb-nextg....
I don't know how it is in Australia, but the contract price discrepancy between Android phones and iPhones is well known in England. For example, O2 sells the Galaxy S2 for free with a 24 month £42 plan, while the 16GB iPhone 4 is free on a 24 month £67 plan.
http://shop.o2.co.uk/mobile_phone/pay_monthly/init/Samsung/G... http://shop.o2.co.uk/mobile_phone/pay_monthly/init/Apple/iPh...
Here, plans are pretty comparable.
Galaxy S2, $5/month on $59 plan: http://www.optus.com.au/store/phone/galaxysii?sid=MobAFeat1:...
iPhone 4 16GB, $7/month on $59 plan: http://www.optus.com.au/store/iphone/plans
The Galaxy S2 plan gives you a bit more data, and you do have more flexibility with Galaxy S2 plans - you can choose to pay more for the phone and less for the plan for example. (Of course, you also have a big choice of cheaper Android phones too).
The reason this is not reflected in the contract-less prices is because US carriers have a very strong incentive to inflate them to force you to choose contracts.