Not all families are familiar with bitcoin but the flight and visa fee reimbursment comes from ASC center and could be made in bitcoin. Wages plus reimbursements are in the range of 1000-2000 RMB per month where anything over 1000 is discretionary by the families. There are no program fees for the au pairs, however there is the upfront cost of buying your plane ticket to China as well as a very low application fee from the processing agency.
Many of the families are near or in Nanjing and Beijing, which both cities have Bitcoin ATMs in some of the public centers.