According to my recipe book I have used this stove 28 times. To the best of my knowledge I have had 2 10 gem returns in the first 6 or so days, since then only 1 gem per day. I feel totally ripped off. Biggest mistake I have ever made in any of the S8 games. I feel this was done to see just how far we would go.
BTW To answer a post above I am lvl 60.