I'm a product of the great depression and saw many ways of saving money. Mother Nature supplied most of what we needed on the farm. One winter the sourdough died. Dad took us to see Grandma and get a share of her starter. It was brought home on a hot water bottle and wrapped in a sweater lest it get too cold and die.
That was in 1938 and as far as I know it is still going strong. I'm starting my own sourdough now. I have been retired over 20 years and been baking just as a hobby. Hope the sourdough is as good as mother made.