We just flew VI Airlink STT to Anegada in February of this year. You're right, when you add up all the ferry and taxi costs, you're right about there. It's a 15 minute flight and it's a gorgeous ride over - the views are spectacular. It was one of my favorite parts of the week we spent on Anegada. RT tickets were about $330 each. Do it - you won't regret it!