One seller on Alibaba has them and if you don't care about all the engravings and such then it's just a Peacock (Dandong) SL-1258 which is dirt cheap like $82+shipping directly from Peacock. It's completely unmarked and it's actually being used in micro brand watches funny enough but that's always an option if you don't care about if it looks right with all the finishing, markings and engravings. Otherwise it's a $300-350 min for the naked movement.