I never said it would cost just a few hundred thousand. The prize money alone is $260,000. But if most countries foot their own bill to attend, throw in another $750,000 and you're at only $1 million.
Throw in another million on top of that for who knows what and you can get a ton of TV, etc and you're still a million short of $3 million. And that makes the $3 million event 50% of your $2 million event.
You could either totally boost the prize money, or host a lot more events (or turn a nice profit), but hopefully the IAAF ensures that big percentage goes back to the athletes but in this case that doesn't seem to be the case.
$500 airfare, $500 lodging (athletes should be doubling up, so this is a $200 a night hotel for 5 days which is about double what it would cost in Boulder), $500 food ($100 a day, they're eating like kings).
That's $2500 an athlete * 200 = $500,000. But I think most federations are paying some of the costs. Maybe not.