Down Button died and sttuck in Dignostic Screen

When I'm back from my second dive, I realized that the left "down" button stopped to work, I tried to restart it, and when it was turned on, opened in diagnostic screen. As I saw in some forums, it maybe a CHRONIC PROBLEM, I contact Internation Garmin Support, and they couldn't do anything and instructed to contact the dealer in Brazil, for my surprise, they didn't check my watch and said to repair it, will coast U$985,00, almost the price of one new.