There was a period in time when $500 or so in FB ads would result in a $5000 sale, so the math worked for me. FB ads work surprisingly well if you target them properly.

In my case, targeting males who were either married or not in a relationship, age 21-40, and then had a variety of interests really narrowed things down.

I gleaned the approach from looking at our 50 or so past customers who all fit that demographic.l