The issue is interviewing in the first place- you'd have to fly out specifically for the interview and hope that it works out. Quite a financial gamble if you do it repeatedly...
Yes, that would be a lot of money. Do companies do interviews over video-chat at all?
I've heard of it happening, but more often with companies in Saudi Arabia an the like, where they have to try harder to get people.
Yes, that is how I got my current job was through a couple rounds of video chat. I'm a Canadian citizen working at a US startup through an I-84 work visa.