> While tennis has become more accessible and lower cost over time, it has always been an expensive sport.

How can tennis be an expensive sport?

My kid just bought (a few months ago) a couple of used rackets for $5. Tennis balls can be had for a few dollars. Courts are free.

Aside from jogging, tennis seems like one of the cheapest sports possible.

I think the only cheaper sport might be swimming, but only if you live near the ocean.