Yeah, the equip reapplying the refund is a bug but it has been reported and the devs said it was a low priority bug. Until it is fixed, Grimthir is definitely the way to go because he just gets cheaper each time Deception is used (assuming the equip isn't shattered).
for my elf statue bg grim will fit like a glove mena dosen't work on it well but since convent was released i say mena