I am referring, of course, to the Kail's Coins quest. Stratics has documentation on coin requirements to get recs for the pre-C5 weapons, but I have not seen any way to find out the coin requirements for the new weapons. I would hate to have to go just randomly collecting hundreds of each coin type (both Kail's and Coins of Magic) before I stumble onto what is needed for the weapons I want to get.
You could talk to the quest NPC about rewards to find out coin requirements.
Or if you're not a royal member, then ask one to.
I've checked it once, because my ally at that time wanted to know. They were standard: 300 Blood Medusa (similarly converted to the same high grade coins, 3 Blood Basilisk) for high-a weapon recipes; 200 Silver Unicorn (~> 2 Silver Dryad) for low-a weapon recipes.
30 Kail's Coins are needed, too.
Basically, the only exception remains to be Sword of Miracles recipe (300 Gold Wyvern ~> 3 Gold Giant). Who would tell me logic behind that, i wonder.