Lucianne wrote:
I spend 400g this morning getting from 269 to 283 but now I'm struggling for recipes to get to 300. Should I specialise?
I don't believe that any of the weaponsmith/armorsmith plans will enable you to skillup to 300. You pretty much have two choices, and neither option is cheap. You can make gear from the Thorium or Radiant sets (plate and mail resistance gear, respectively) or you can make items from the Imperial Plate set. You should see Thorium/Radiant plans on the AH, or they can attempt to farm them as world drops (Un'goro Crater was fairly kind to me). You can buy the Imperial Plate recipes from Derotain Mudsipper in Gadgetzan, Tanaris.
Lucianne wrote:
What will specialising give me or allow me to do? will it give me access to more plans?
Specializing will give you access to a small number of trainer-taught recipes that can only be made by blacksmiths with that specialization, including some epic pieces.
The tables on Allakhazam's blacksmithing site provide some info regarding which recipes require specialization to learn:
http://wow.allakhazam.com/db/skill.html?line=164&source=live&tier=artisan (pre-BC)
http://wow.allakhazam.com/db/skill.html?line=164 (BC)
Please note that many pre-BC items that formerly required specialization (as depicted on the pre-BC page) are now available to all blacksmiths. I believe that anything that is learned from plans (vice a trainer) is available to any blacksmith at the appropriate skill level.
Lucianne wrote:
Do I need to specialise in order to make the epic items at 375?
It depends on what you mean by "the" epic items. Some recipes will require specialization. Many recipes at lvl 70/375 skill do not.