Off topic to bullet prices, but this has been true since COR was introduced (with a blip in Abyssea times due to atma). If you add COR damage + the 10-20% it adds to the other DD's through buffs, COR has always been the premiere DD in the game. Back in Colibri days it was well known a BRD/COR/RDM/DDx3 was better than a BRD/RDM/DDx4 party.
But back in those Halcyon days I could craft steel bullets for 12k/pouch.
Admittedly ease of gil making has led to inflation in ammo prices but 100-150k/stack is particularly ludicrous. Fortunately I do know a synergist in my LS that can make the O. Bullets. But still not going to use them for Wildfire. Seriously going to look at levelling the crafts and synergy for this since likely this will be the endgame bullet for COR.