We have brokered a transfer of legacy space from the APNIC region to a buyer in the APNIC region.
As part of the process, the seller was allowed to pay a partial fee to temporarily attain member status.
I think it was processed under APNIC policy for the transfer of historical resources.
However they did it, APNIC did vet the seller as the owner of the address rights before the transfer was completed, as mentioned in step 2 on the page above.
Hope this helps.