In the coming patch you'll be able to convert 10 Ink Of The Sea to one Snowfall Ink so it should be a bit easier for Scribes to make the Darkmoon cards...but that said, Inscription isn't much of a moneymaker until you research the most popular glyphs. Then you can make a moderate amount of money from it...but you'll see more money from other profs like LW and JC.

Cheers,
S.