@Keith ******
to GET an OA visa in your country before you come here you are correct the proof of funds can be shown in a bank in your country.
BUT
once you get the 2 years you can stay ON an OA visa here by maxing the visa out if you're going to apply for an in country yearly extension you either bank the 800K in funds or you have transferred in the 65k every month for the previous 12 months. (if your embassy here doesn't issue the income affidavit notary)
OR
You go back to your country and buy a new OA and repeat the process.