Honestly, I think your best bet would be to do some price shopping. I'm not sure what country/area you are from, but that price sounds a bit high. I would ask if that quote they offered is a "maximum". In other words, that price they gave you is probably intentionally high to cover themselves for most possibilities.
If possible, can you also post pictures, especially of the dial and ring, and a picture of the safe door itself.
I always get excited when I hear about these type of safes cause you never know what you'll find in 'em. I once opened a safe for a family whose grandfather died, and the safe contained approximately 10,000 in margarine containers.
Good luck, and keep us posted.