What will the CRL end up costing?

The Herald reports:

Only 12 months ago, the city’s top transport bureaucrat was assuring Aucklanders the rail link could be built for as little as $2b.

Auckland Transport chief executive David Warburton said in July last year the cost estimate for the 3.4km underground rail tunnel remained at $2.5b, plus or minus 20 per cent.

Two months later, Bridges and Finance Minister Steven Joyce revealed the cost had increased to between $2.8b and $3.4b.

So from maybe $2 billion to maybe $3.4 billion.

Pressed on whether he had received any advice from officials on the figures moving above $3.4b, Bridges said: “I think I would say they have moved around.”

The briefing papers, obtained by the Auckland Ratepayers’ Alliance under the Official Information Act, say “we cannot be confident at this point that the changes to the CRL cost profile will not lead to a reduction in other current planned transport expenditure”.

Sounds like that is code for increased costs. Anyone think it won’t cost more than $4 billion?