Last night, for the first time ever, I dropped a 375 profession. I've never gotten rid of one before of any rank, let alone a maxed out one, but mining is gone. I woke up in the middle of the night, stressing out that I don't have it. I am no longer one of the guild's go-to people to break primal earths or manufacture Hardened Khorium. I can't mine all those gems in MH and make like 20g per run anymore. Any Rich Adamantite nodes I run across will go unloved. /slow tear
Instead I'm now the owner of 375 points in Alchemy and a Redeemer's Alchemist Stone. I leveled from 1 to 375 last night in the span of maybe 3.5 hours. The total cost was around 1.5k gold (mats, skills, recipes), although I had about half the flowers I needed from my lowbie herb mage alt and a bunch more from a friend. Fozec even loaded in with my other herb alt and picked some carrots for me. The most expensive part by far was making the various stones to get the trinket. Primal Mights and Fel Lotus were not cheap on the AH. I also paid some semi-ridiculous prices for a few high-end flowers.
But unlike JC, you can level the entire way with 100% vendor bought recipes. Sure, I had to cruise around to some quartermasters, and Fozec engineered out to the dude in Tanaris for the first stone recipe for me, but at no point in time did I have to plunk down +300g for a world drop recipe just to get the last few points.
From a raid healing standpoint, the basic Alchemy skills + reasonable rep net you Transmute Earthstorm Diamond, Elixir of Healing Power, Adept's Elixir, Elixir of Draenic Wisdom, Flask of Distilled Wisdom, and Super Mana Potion. While I was leveling up, I discovered Flask of Mighty Restoration.
This really only leaves me Elixir of Major Mageblood to keep an eye out for. It's a world drop and goes for about 1k gold on the AH. I've never seen it, or even the elixirs for that matter, on our Horde AH. I'll also probably start trying to get the Ironshield Potion recipe out of Old Hillsbrad for our tanks. Right now only one of our Alch in the guild has it and they're not always on.
For general raid consumables, I could work on acquiring Major Arcane Protection Potion (Drops off Vir'aani Arcanists in Nagrand) and Major Shadow Protection Potion (Drops off Shadow Council Warlocks in Shadowmoon Valley) so I can start making those for raids and maybe discover their associated cauldrons.
Looking at specialties, Flasks are considered Elixirs, so Elixir Master would probably be the best choice for raiding healers that fly solo most of the time. Right now, though, we have about 5 Elixir Masters and only 1 Potion Master in the guild that I know of. I'd have to go to one of the Elixir Masters to get my EoMMageblood made anyways, so it's not a big deal if I go Potion Master to help out the tanks. That's assuming I get the recipe to drop for me.
You can change specialties anytime for 150g. When you first do one, there's a quest involved that makes you gather up mats and some item from an instance. If you switch mastery, you instantly learn the new one - no quest involved. From what I've read, it's cheaper and easier to do Potions and drop it for Elixirs. There's a significant cost difference in the mats (even including the 150g respec'ing fee) and Elixirs will take about 5 runs through BM while Potions is a book off the 2nd boss in Normal Botanica.