RicF - no doubt the costs of representing your country put many, who could do very well on the international stage, off. and frankly if the destination isn't within relatively easy, aka cheaper, reach we wouldn't either. my missus did the World's in Lausanne in 2006 and no doubt she could have been in the GB squad every year since but when the competitions are in places like Beijing, Vancouver, Wellington NZ, Turkey, Israel etc then just the costs of just getting there make it prohibitive especially for 2 people with a business to run and a life to lead.
but as you say, there are those prepared to do it - much like many who do IM after IM hoping to get to Kona and pay out a shedload more to compete there.
there's been a pretty active thread over in Tripetalk this week about the costs of competing in the UK causing long standing triathletes to bail from further competition as it's getting too expensive - translate that up to international competition and it's no longer a cheap sport. OK, it's never been cheap but in relative terms it's bloody damn expensive now.