I am only transporting any meaningful stuff on the way back. If I "ghost teleport" to Bakti from Hylls I basically covered half the map in seconds and I am as close to Calx and all the jungle materials in Hylls as in Bakti. I realize you can already do this with the "home teleport" but the fact that it limits you to just one town has some significance, I cant teleport today to Bakti to get a Campodon and tomorrow to Meduli to get a desert horse without actually traveling there. And it may seem unimportant but if you combine this with a service like the one provided by the Royal Bank of Tindrem where you can just transfer your gold from any town to any town for a small fee you don't even have to bring the mats yourself to setup a temporary farming base anywhere on the map.
(edit: in fact would love to hear
@Angelo 's take on this or
@Ibarruri as I suspect having this ability would devalue the service they provide)
Is it game breaking or not depends on your take, I am not even sure myself but its not as innocuous as you are putting it.