He did calculate the cost of this, and gave the order regardless. This is the most worrying part of the current events, because it implies that more is to follow, and not just in Ukraine.

As far as what is and isn't what's valuable, you're ignoring the ideological dimension. Putin's favorite philosopher is is Ivan Ilyin, whose take on politics was basically Eastern Orthodox fascism. Ukraine itself, to Russian nationalists, is the single largest chunk of land that is "rightfully theirs". If Putin can pull the invasion off, he'll be a hero with that crowd.