We don't seem to have (m)any expats or Australians on the site yet, but I'll share what I have learned. I'm taking advantage of your profile information listing you as a software developer.
A friend of mine is currently doing a study of national IT professional societies for his MBA project. One of his goals is to understand which funding models are effective in the absence of mandatory licensing. (Consider: Most developers don't need to be a member of an organization in order to practice.)
Such organizations you or others may be familiar with are the British Computer Society (BCS), the Canadian Information Processing Society (CIPS), or in the U.S. the Association for Computing Machinery (ACM) and IEEE Computer Society (IEEE-CS).
To the point: My friend told me recently that the Australian Computer Society (ACS) makes money by assisting the Australian government in determining immigration eligibility. So I went to the ACS site and started digging:
"The Australian Computer Society (ACS)
is the designated professional
assessing authority for persons
seeking to apply for Skilled Migration
as IT (Computing) Professionals [...]"
See ACS's Pre-application Skills Assessment (PASA) page. That page also links out to the Australian Government's Department of Immigration and Citizenship, in particular to a document titled General Skilled Migration (PDF). Here are some interesting points I discovered, relating just to fees:
The government recommends if you do want professional help to use a registered migration agent. There will be fees for such an agent. See MARA - What does it cost to use an Agent? Currently: AUD1500 - AUD4000, or ~ £850 - ~ £2270.
There will be a fee for the immigration application process itself. See Professionals and other Skilled Migrants visa charges - outside Australia. Currently: total of AUD 6035, or ~ £3420.
Also:
"You also need to have your skills
assessed by the relevant assessing
authority as suitable for working in
your nominated occupation." (page 7)
... and you need to do that before you even apply. The ACS Costs and Charges page shows a cost of AUD 400, or ~ £225, for the PASA (General) application.
So, I think the answer is yes, you'd certainly want to have ample savings to cover the red tape stuff; perhaps ~ £6000 judging from the above alone. Add your travel, moving, and living expenses, etc.
Best of luck! Australia sounds exciting. (Have you considered Canada? ;-)