Erm, why is making yougurt at home expensive? I mean buying a cow and keeping it in your hallway - sure. But you can make pretty decent yogurt with store-bought milk and some blankets. Though if you want to use real "straight-from-the-cow" milk, you do have to take a trip to some nearby village maybe once in a week or two. I'm not sure what you mean by "make yogurt at home".
And speaking of homemade, did you like that strawberry jam I gave you?