Reading is an affordable hobby. Libraries and websites like Project Gutenberg offer free access to books.
Hiking in nature is a low-cost hobby, with free access to many trails and parks. Annual passes offer savings.
Cooking is the most popular US hobby, and baking can be affordable with basic supplies and inexpensive ingredients.
Starting a garden from scratch can be cost-effective, starting with seeds and progressing with improved skills.
Writing requires minimal investment, with free resources available to improve skills and earn as a freelancer.
Starting painting and drawing doesn't have to be expensive; cheap supplies and how-to guides are readily available.