So, you combat that by :
1) Be visible. Have code up on Github that I can see.
2) Offer a month to month contract. 15 day notice for termination. This gives you and the company an easy way out if things don't work out and the added bonus of not having to deal with messy tax issues across country borders.
3) Flying is only expensive if your hourly rate doesn't justify it. Honestly, if you're approaching a company with some incredibly low number, e.g. $15/hour, even if that's a decent wage for your country, as a manager, I see that as a signal of cheap, inferior labor. Increase your rate, e.g. $100/hr, so that you could fly if you had to.