Interesting price. Even in Zone 5 I wouldn't mind paying £1.77/minute to say "Hellllllllllllllllllp the boat as sunk"
Another advantage of the phone is the ability to tell rescue services, numbers of people on board, medical problems and whether your in a life raft, floating etc etc, is not possible with an EPIRB. Also with the GPS location transmission it looks like a winner.
Also the ability to phone the misses to say "We'll be home at 7.30pm and make sure the wine has breathed and the dinner is on the table" when your half way across the channel.
But knowing me, the battery would be flat and the line engaged!!