I think an error was made when the teleport prices were altered in patch 6.0.

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Area and coordinates: The Gold Saucer
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The old system of teleport pricing was based on your distance from your destination but the Gold Saucer was only charged at half the actual cost by distance.

I happened to save a record of the old price lists, so can quote the prices from them.

Comparing prices for teleporting to the Saucer versus the nearby town of Forgotten Springs, you can see that the price is about half of what it should be based on distance.

From Limsa: 233 gil to the Saucer vs 479 to Springs
From Gridania: 249 vs 473
From Ul'dah: 79 vs 158


However, whether deliberately or not, this discount seems to have been left out of the revamped pricing list introduced in 6.0.

Under the current system, the same price comparisons are:

From Gridania: 408 vs 379
From Ul'dah: 120 vs 105

The slight price difference between the two destinations seems correct for where they are located relative to the starting points, but it's clearly not giving a discount like it used to.