I take the maillotpois approach.

When I find shoes that I really really like, I don't hesitate buying another pair in a different color, because I KNOW they will be scarcer than hen's teeth once the manufacturer catches wind of the fact that I like them.

Case in point: my Ecco sandals. That particular style isn't made anymore and I'm very glad I have a both a black pair and a brown pair. The brown pair is starting to wear out finally, and I wish I could replace them, but no luck.