I found a $35 each price for (After-Market; Z22A Li-Ion - 3.8 V d.c. / 20.0 mAh - ZeniPower).
If you look for EBay sellers who also frequently sell Oticon More hearing aids from other than USA countries and inquire about purchasing rechargeable batteries for Oticon, then you are likely to find the same. Hint South Korea/Germany. Though the first SK-source was like $79.
I think that the off-again/on-again EBay seller who keeps replenishing his stash of Z22A batteries and selling them for $65USD is likely purchasing these from the $35 source.