If you want to, you can use colloidal silver to force the plant to make pollen. Seeds made from that pollen will be fem. If you only treat one branch and self pollinate the other parts of the plant, it will be a stable copy of the mother.
Not a difficult process, and certainly cheaper than $10/seed. Plus, if you live in a red state you don't have to worry about getting seeds in the mail.
You may be a a little late this cycle. You want to start just before the plant starts flowering and for a couple of weeks beyond that. You need time for the pollen sacks to mature, then for the seeds to grow and mature.