I think those numbers are impacted by outsourcing market a lot. As discussed here multiple times, when you work remotely for a company without a middle man, other rates are applied.
With Basecamp, for instance, you'd get proper pay so you'd be able to afford flight tickets for a conference, which is not the case with rates in this article.
Disclaimer: born, lived and worked not too far from Armenia; worked in outsourcing for a good chunk of my early career. I'm a strong advocate of location-independent fair salary and hope other companies will follow Basecamp's lead.
EDIT: typo.