My husband likes to shop at Costco. I don't like it so much, but sometimes we go together because it's easy to buy things that are quite expensive at regular supermarkets. We bought quite a bit of kombucha over the summer.
However, through a friend's connection, she shared her kombucha scoby with me and my husband has started making homemade kombucha at home.
The left side in the lower picture is the Scoby, and the right side is green tea, black tea, and sugar, and he leaves it for a few days. It's a lot of work and it's expensive to buy it.
And it tastes pretty good!