This is something that the ECB has faced with several of its unconventional policies, not least its Outright Monetary Transactions (OMT) programme that was launched in the summer of 2012.
Such costs include: Revamping the IT Systems and or acquisition of new Systems, training costs for staff and additional staffing needs, insufficient historical data, time consuming transitions, Internal models and risk quantification costs and disclosure overload. As to whether these associated costs will be transferred to the beneficiaries of financial services remains a subject for research and discussion within the sector. Thank you!