The colder the winter, the thicker (and therefore more valuable) animal fur. The most valuable fur is in animals of a sharply continental habitat (sable). Winter is milder on the Russian Plain. The fur of the Arctic fox, a resident of the tundra, is more valuable than the fur of the marmot, an inhabitant of a territory with a warmer climate.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.