You can legally buy Polar Bear hair from dealers who have leagal rights to purchase and sell. I friend of mine from Spokane bought some for me last year. I haven't tied any flies with it and have misplaced it and can't find the darned stuff. It was a small, like 3X2 inches, for $10.
Danielson's polar bear packages contained a rather small patch of hair but it was of pretty good quality; no broken tips, urine stains, etc. Shoff's Sporting Goods in Kent (back when it was a fine fishing and hunting emporium operated by Clarence Shoff of Polar Shrimp fame) carried a full range of Danielson's polar bear. I don't remember how much it cost.
Just got registered on here a couple weeks ago and was going through some old posts about polar bear hair, in particular a query about a piece going on ebay posted in late August which apparently sold for about $170. I thought polar bear skin is black, not tan like the picture shows. PB skin is black to maximize warming when out in the sun so buyer beware.
It is a common misconception that polar bear skin is always black. Most of the time it is some shade or brown or tan. These bears don't get their warmth from the sun, they, like other mammals, produce the heat themselves from burning food and their fur insulates and keeps the heat in. Also, polar bear hair can be white or any shade or cream up to what is like a very light tan, and can have all these various shades present on one bear.
I've seen quite a lot of polar bear (skin) living up here and all of the polar bear I have ever seen has black skin, thats how you tell. And it is black to absorb sunlight, even though they are warm blooded they need all the help they can get.