Butter

Not that this is a money saver, but it is fun to try.

1 pint heavy cream
pinch salt

Pour in a quart size jar, with tight lid. Seal well.
Shake, shake, shake, roll, dance, whatever until the butter has separated from the buttermilk.  20 minutes or so.  Enjoy homemade butter!

For the buttermilk, you can make yogurt, bread, or cornbread.