Moed Katan 13: Better to Do Mitzvot!

A Canaanite slave and the value for such a person to be a member of a Jewish household. Plus, 3 mishnayot. So, no large purchasing land or large animals, etc., unless it's for the needs of the holiday, for yourself, or to provide the most basic of income to the seller. And other activities that are prohibited, but context will determine whether there's room to permit them. Also, emmer wheat.