FWIW, I suspect most people attending anything like this event in a foreign country would need to spend a day travelling either side of the event, which inevitably adds to the overall costs.
Sure, we might all want to go to an event within walking distance of London Heathrow / Stockholm Arlanda etc, but that is both highly unlikely and possibly even more expensive if not well supported by low cost airlines - the hotels are almost certainly to be more expensive precisely because of their location.
Heck we might as well consider meeting in Adepticon (right by Chicago O'Hare) as a potential venue, provided we give them enough warning to allow us to set up the required number of tables . . . . .
(I would love to go; I have cousins living in the area, though the air-ticket is still too much

)
We all agree that cost, travel constraints, location and general timing are key but this is an exercise in compromises, with cost being the main issue for many / most people, and travel constraints / timing running a close second. Basically you have to be *really* dedicated to attend in a different country, which is why there has been so much difficulty getting people to come over to the UK