Creation magic takes more in theory cuz you are using earth magic wind fire water metal etc and condensing it into a singular defined shape, but for someone alleged to be nearly as powerful as a demigod and capable of destroying half the world, killing dragons insanely, creation magic seems literally useless to anyone even with the creation gods blessing, as creation of anything material consumes too much for anyone to handle, he has millions of mana, royal court magician only has 10k. Meaning that the magic is less useful than all others, as retaining solid form can be done with earth or ice magic, creation doesn't even help his crafting, it's weird
Edit got number wrong, but creation magic as a basic form should take the same as other elements in most, eg wind magic costs the same for intermediate as earth or fire, is harder to detect or avoid but weaker than fire
For a creation God lvl 10 blessing and 200x the highest magician in the land, you think he'd Be able to create more, otherwise the creation gods blessing means nothing and creation magic lvl 10 means nothing since it only seems to be used for him to google stuff (a power Gods are unsure if he should even have) while in theory it could he classified as the ability to make whatever magic you want, casting magic with any element doesn't require creation, and a decent amount is permanent
Edit 2: also the scaling is not standard, a 30 cubic meter storage is a national treasure even before all the enchants and materials, but his conversion to yen implies its only worth a few hundred grand, which is nice but most first world nations have billion dollar jewels and art, something under a million without historic value isn't a treasure, and something with historical value under a million doesn't have enough value to make it worth preserving in govt collections