The Grade-II listed public toilets closed 15 years ago and the new owners can expect to spend more than a penny renovating the concrete building.
Built in 1923, its symmetrical neo-classical facade has earned it its listed status.
It is expected to become a cafe or restaurant for tourists, with a view of the beach and Bristol Channel.
A heritage "loo with a view" has gone on sale in Barry Island and is expected to fetch more than £50,000.