Considering the time costs of upgrading a Mythic through Magian Trial and the existence of Empyreans that are relatively easy to get and comparable, I think something needs to be done to make Mythics easier. I understand that with new upgrades on Salvage armors there might be more interest in Salvage and Alexandrites might be available at all (haven't seen one in six months on my server), but even then something needs to be done.

A vendor who sells Alexandrites for 5K would be enough. This still keeps the price at 150 million gil for a Mythic, but it opens up the option of people undercutting the vendor to everyone's benefit.