I work in supply chain but not a complete expert but the smallest cheapest working order freight ship I can find for sale is this one for $6MM, doesn't include licensing, crew, insurance and the dreyage/accessorial on live polar bears is gonna cost you big
Idk, polar bears are really heavy, and it takes a long time to get from one end of the planet to the other, so you want something secure to store the bears in. That means a bigger ship that can handle angry bears hurling themselves at the walls of their cage, because they will wake up during the journey, and they won't be happy.