If you spent anywhere near that amount of gil attempting to make a teleport earring, chances are your skill is far below the cap for this synth. It's just like regular crafting... if you're too far below the synth cap your chances of success are very low.

While I admit that lowering the cap on teleport earring synths would make these earrings more accessible to the general population, I'm willing to assume that the failure to make one is simply due to misunderstanding the system itself, or insufficient skill level. Cause they're really easy to make lol