Right now Teleport to a Crystal costs something like 50-650 gil. I was thinking about the Ascian ability to teleport from point to point in the storyline, without Crystals. This seems like something a Black Mage should be able to do at high levels. To make it fair, it could also be a new Black Mage Cross Class Ability similar to Swift Cast.
There is a Teleport function for Married Couples, that is free. I was thinking of something similar, but less free.
first, it would wipe your MP, second, it would burn up either a new crystal item, or an existing crystal item, such as 1 Fire Crystal or 1 Water Cluster. It would allow you to teleport to the location of a Party Member, similar to an improved version of the Black Mage power to travel 30 yalms.
Alternatively, you could "save" a point or number of points (like 3 max) and basically recall to that spot. It could be further limited to the "same map". Setting your "spot" would be like setting a Waymarker.