I'd love to use it always, but it looks too much like a gil drainer. I am lvl 26 with 21K in my account, I don't believe I would have a gil left if I used it all the times I wanted going straight to the closest place. What I did has been to register a favourite location in all continents and when I need to travel I go for the cheapest option. I can't believe the ferry can cost more than the teleport in some cases, though.