The answer is simple - quality gym chalk is hard to come by. The best chalk is made of magnesium carbonate, which is naturally mined from the earth. This natural resource is becoming increasingly rare and more expensive to source, making the cost of gym chalk higher. Additionally, the process of making gym chalk is labor-intensive and requires specialized equipment, driving up the cost even further. However, chalk prices also depend on its intended use. Gym chalk becomes expensive because its source and texture matters for the consumers.