The price of a good gymnastics mat can shock many parents. Such mats are so pricey, however, because of the materials.
Both the foam and covers are expensive because of their durability. They need to withstand high-impacts and protect the people using them. Shipping is generally a pricey matter, too, though sometimes you’re lucky to find a good deal.
And while you may pay more than you’d like, your child can get a lot of health benefits from gymnastics, such as flexibility and strength (source).