I was referring to https://www.privacyshield.gov/Program-Overview where single framework (EU-U.S.) for companies with between $0-$5 million the yearly fee is $250. If you want to add Swiss-U.S. privacy shield as well, then $375 per year for both.
>>cbg0+(OP)
Thanks - I have no idea where I got the $500 number in my head. Maybe I was thinking of one of the private mediators I was researching? Sorry for questioning your initial number...