There is increasing grumping at escalating costs of London's 2012 Olympics, and even mischievous attempts to extrapolate that this inevitably means Glasgow faces increasing costs over the 2014 Commonwealth Games.

We hate to sound evangelical, but there's no comparison between the two events. The Glasgow Games are budgeted at £375m, including public investment of £298m. With 70% of facilities built, there is good reason to believe there will be no repetition of London's escalating costs. The main Olympic stadium alone in 2012 will cost £500m, which will take a lot of recouping, never mind an overspend hurtling towards a total cost of £10bn.

However, there remains evidence that major events bring significant income if managed properly. There are opportunities to be taken.

The news this week that the Sudirman Cup World Team Badminton Championships last year was worth £6.69m to Glasgow underlines the importance of successful major sporting events to Scotland.

The figures are from a report commissioned by Glasgow City Council, EventScotland, and UK Sport. There were 1000 competitors and 500 officials from 49 countries at the eight-day event, and over 200 hours of worldwide broadcasts.

Of the £6.69m, more than half (£3.5m) was spent by 15,000 visitors from outside Scotland. Winning the right to host the tournament cost £745,000 of public sector money. "The economic impact of the event shows a solid return on this investment," claims Paul Bush, chief operating officer at EventScotland.

The badminton championships, held on the run-in to the 2014 Commonwealth Games vote, was one of several partially bankrolled by his organisation to help the city establish its credentials, with the added goal of making the country a major events venue. The value of EventScotland's international portfolio is estimated at £293m.

"This is one of the fastest growing industries in the world, and results from this report show that Scotland is well placed to capitalise on this trend as people travel here to see sport and cultural events," said Bush.

Despite two previous Commonwealth Games in Edinburgh (1970 and 1986), the 2014 edition will be the biggest sports event of any kind ever hosted in Scotland, and will be quickly followed by the 2014 Ryder Cup at Gleneagles which is expected to earn £75m. That's 25% less than the 2006 Ryder Cup (Fáilte Ireland and Ryder Cup Europe).

Golf tourism is a huge earner, worth more than £300m annually to Scotland. The 2005 Open Championship at St Andrews alone was worth £72m: £40m of promotion in worldwide TV exposure and a net benefit of £32m in new money for the Scottish economy as a result of spending by spectators, media, players, and the R&A (Scottish Enterprise and R&A figures). Last year, on top of comparable TV worth, the economic impact was £14.8m. The Open returns to Scotland next year (Turnberry) and 2010 (St Andrews).

The 2003 Champions League final at Hampden was said to be worth £25m to the city, while last year's UEFA Cup final was worth £30m.

Yet Glasgow 2014's projected benefits seem massively modest by comparison. A feasibility study commissioned by then First Minister Jack McConnell, under the chairmanship of David Mackay, projects net economic benefit for Glasgow, based on figures provided by the PMP consultancy, of £26m. Across Scotland it is £81m, plus a net gain of 1000 jobs in Glasgow and a further 1200 around the country. It took PMP three months to come up with the analysis, and yesterday we asked them to comment on the figures and methodology, in the light of such significantly higher benefits elsewhere. Glasgow 2014 indicate they were happy for PMP to do so.

Yet despite the raft load of public money they have been paid for this and other government-related projects, they declined to comment.

So we decided to look further at other major events. The Manchester Commonwealth Games in 2002 had a economic benefit of £1700m and created 6100 jobs, according to government figures. The state of Victoria's gross product around Melbourne 2006 was up by £771m. These Games created 13,000 personal years of full-time equivalent employment.

But they are all kicked into touch by rugby. Last year's World Cup brought an estimated 400,000 extra visitors to France. It delivered, according to the International Rugby Board, a total economic impact of £3166m. Total attendance reaching 2.25m, an average 47,000 at the 48 matches in France, Scotland and Wales. A total of 8500 live TV hours were broadcast worldwide.

There's no guarantee that any sports event will be a financial success. Edinburgh learned that in 1986, when their second Commonwealth Games suffered a £3m deficit on a £27m budget.

But even on the periphery there are rewards for the enterprising. Dave Williams, Bush's predecessor at EventScotland, told me that Queensland, the state whence he came, had benefited by £670m in the wake of the Sydney Olympics.

All this suggests benefits of hosting the 2014 Commonwealth Games in Glasgow have been seriously undervalued.