Have you leveled Inscription? Have you done the 79 (or thereabouts) days of Northrend and minor Glyph research to learn every glyph you can that way? Have you purchased or farmed the 57 Books of Glyph Mastery? Have you trained all 143 trainer glyphs and purchased the few you buy as a technique? I have. Those books, when you can find them are expensive. Farming them is worse than the cost you might pay at the auction house. I’ve endured a bit of metaphorical pain to know every glyph that’s out there.