Looks like they are kind of expensive:

> Now you can buy one. Actually, you can buy eight in a 16-pin DIP package. It will, reportedly, cost $240 for the 16-pin DIP. That’s only $30 per memristor, and it’s the first time you can buy them.

From: https://hackaday.com/2015/07/02/new-part-day-memristors/