Did not realise it was that much:
'Non-Findmypast.co.uk subscribers should use The National Archives Freedom of Information (FOI) request form to request a search of closed records from the 1939 Register. If the record can be opened, we will send you a full transcription of the information held in the record. The opened record will be available to view on Findmypast.co.uk ten working days after the notification of a successful request. Please note there is a fixed charge of £24.35 for this service.'
I think that scotlandspeople charges a similar amount for anyone on their 1939 register, and you only get to see the person you specify, not the surrounding household, so perhaps it is not too bad if you were desperate, but another few months now should not matter.
Added: £15 for scotlandspeople per entry.