UOC Universitat Oberta de Catalunya

[Sagan]

This seems to be quite a catch. Degrees are recognized in Spain (not propio). Tuition is in English. Fees are miniscule. The work is done online. Foreign credential evaluation services in the U.S. have successfully evaluated the degrees as comparable to those from regionally accredited schools in the U.S. Degrees from this school are accepted at U.S. schools for admission to higher degrees. The university is ranked and known.

A three-year journey to the PhD would cost approximately $US3,000, total.

Assuming you want to pursue one of the 8 doctoral degrees they have on offer, it's hard to see why this wouldn't be a good choice.

Could you please tell how did you calculate this?

On an abacus. Old school. The numbers are on the website.