Howdy allanb and welcome to the forums from an ex-melbourne boy (grew up in the inner south east). The info you get here is all pretty good stuff. In relation to what the bike stores are telling you, you don't have to spend 5,000 to get a comfy ride.
Absolutely key is the right size bike - 2,500 spent on the right size is better than 5,000 on the wrong size. In other words do the bike fit thing. The extra money is mostly for performance (lighter groupset, lighter wheels etc. and not necessarily comfort).