The whole idea of the flamekissed armor is to get money. ArenaNet is not going to make this for free when they can charge a little for their work (and since people can buy gems with gold, they are already cutting their revenues).
After all, this is why we have a Gem Shop, to get shinies and support the game.
So my suggestion would be: Sell a recipe to update our armor in the Mystic Forge (I would like if this apply to any armor but since ArenaNet did the human T3 already, they should keep going with the rest).
Of course, they can make more people happy if they also sell recipes for each individual piece.
So lets say:
Full set (6 recipes): 800 gems
Individual recipe: 200 gems
The recipe can work just like an Ascended Inscription, example:
Recipe: Flamekissed inscription.- Using the sheet will bring up a menu allowing you to choose a specific recipe (helmet, shoulders, gloves, etc).
Now the recipe may include mats or things we can get from Miyani (since people will buy this with gems, there is no need for excessive/expensive requirements) and of course, the original T3 armor.
So at the end we throw at the forge: 1 flamekissed helmet recipe, 1 cultural T3 helmet, 1 Molten Lodestone and 5 Philosopher’s Stones.
And of course, the idea to use different Lodestones to get different effects is great.
Why fix the Necromancer for free when we can charge $$$ for the Revenant
-ArenaNet