I've always wondered how the mules by the warp taru get such large quantities of silver coins? I must be missing something here. If one Gold coin costs 1k IS which converts into 5 Mythril coins, then into 2 (10 all together) silver pieces, they would run out of IS pretty quick and still wouldn't have as much as they would. And if they bought a stack of 99 Silver peices on the AH, they would come out to exactly 1212.12gil each, which they sell for (on unicorn at least) for 1.2k.
So my question is this: how is this at all profitable for them? They must make a killing doing so, obviously they have some sort of secret (that I'm obviously missing).
Just curious.