Build them and they will come.

That's the overwhelming philosophy on convention and exhibition centres -- erect new ones or expand existing facilities and the visitors, and their cash, will roll in.

The City of Vancouver joined the intense competition with full vigour, deciding in 2004 that its facility was undersized and losing the city convention traffic.

The man in charge of the Crown corporation that runs the Vancouver Convention and Exhibition Centre brims with confidence that the new facility, scheduled for completion next year, will be worth the vast sums of money that have since flowed.

And they are vast.

Costs have gone from the original estimate of $495 million in 2000 to the current $883 million.

"If you compare the expansion (costs), we're in the cards,'' said Warren Buckley, president and CEO of PavCo, the Crown corporation that runs the centre.

Boston has a new convention centre that cost $850 million "and it's not as nice as the new one here.''

Phoenix's new centre cost $775 million, Chicago just expanded for $800 million, Cleveland is proposing a $400 million expansion and Ottawa is considering a $400 million expansion.

Currently, there are about 20 centres being built in North America and another 20 or more expansions, said Buckley.

Buckley conceded the convention centre market is saturated, but maintains Vancouver will be successful -- the expansion tripling the current exhibition space on the waterfront at Canada Place.

Despite Buckley's optimism, the province's independent auditor general has reservations.

In a recent report, acting auditor general Errol Price said that although the latest approved budget was for $883.2 million, "there is no guarantee that this will be the final cost.''

The project was plagued by problems from its outset, the auditor general said.

The federal government came on board with a fixed contribution of $222.5 million and the province, initially matching Ottawa's contribution, has been left to approve and fund the budget overruns.

A decision to turn the expanded facility into a showcase for the 2010 Winter Olympics and use it as the Games' international media centre expanded the scope of the project, and put it on an accelerated completion schedule that forced up costs, the report says.

The total B.C. taxpayer burden is now more than $500 million, surpassing the infamous fast ferry fiasco under the previous NDP government.

When the auditor's report came out, Finance Minister Carole Taylor brushed off the comparison to the PacifiCat ferries -- a trio of aluminum ships left on the auction block even for a fraction of their $469-million price tag and eventually mothballed.

"At end of the day we'll have a magnificent convention centre that we will all enjoy . . . and it will not be wrapped in plastic,'' Taylor said, referring literally to the ferries' protective cocoons.

Heywood Spencer, a professor of public policy at the University of Texas in San Antonio, and an expert on the economics of convention centres, is skeptical.

Some do better but many get a half to a third of the visitors forecast, he said.

There has been a decline in air travel after the 9-11 terrorist attacks in the U.S. and rising energy costs, he said.

"It was devastating,'' he said, referring to the drop in delegate days at convention centres since 9-11. "And now energy doubling will be devastating.''

Convention business at the most successful destination in the U.S. --  Las Vegas --  is in decline and the biggest convention centre in the U.S., in Chicago, expanded and still saw the number of delegates drop last year, he said.

Peter Hall, who teaches urban studies at SFU, said there are no shortage of examples of vast overspending at taxpayers' expense, including the Olympic Stadium in Montreal, Mirabel airport outside Montreal and Chunnel between England and France.

"Given the cost overrun and given the changed circumstances, it's very hard to see how that convention centre can have a net positive cost benefit,'' he said.

Buckley is undaunted.

Already, he said there is a 6,000-delegate convention of geneticists booked for 2016 and the 2010, 2011 and 2012 bookings are all "very good.''

One recent convention of about 2,000 generated $4 million in direct spending, he said.

"The genetic doctors at that rate will spend $12 million.''