Leveling a profession on one of my alts for like a 100th time, I once again realize that existing profession leveling guides have several flaws. First, they're usually written in english, so if you're not using an english client, you will have to translate all required items before searching for them on AH. Second, most importantly, auction house prices and availability vary so much that it's impossible to make a guide that would optimize your budget.
However, its all easily possible with an addon. So here's my idea, though I wanted to make sure such an addon doesn't exist already.
We select a profession, and click "optimize". The addon searches the auction house and chooses the most optimal way to level a profession. Then, perhaps it should make buying individual items easier - e.g. if we need 120 ore, it should figure out which stacks to buy (there should be some kind of tradeoff so we don't end up buying 120 stacks of 1 ore because its 2% cheaper) and.. well I'm not sure how much you're allowed to modify auction UI, but surely there's something one can do to simplify that. Last but not least, it would show a list of things we need to craft (and possibly recipes we need to buy, we could configure if we're allowed to use non-trainer recipes).
I'm sure these ideas aren't new, but I couldn't find any addon that would do that. Besides, it should also be possible in web form, since the api to get an auction dump is available.
that's an ancillary goal for gnomeworks. it can kind of do it, sort of, but it could be better.
there's no "optimize" button, but you can pre-plot your skillups based on current costs from the ah and your available inventories.
if you visit a trainer, it will record the levels at which you can attain new abilities and it knows the skill up chance for all skills, so it can predict the skillups for each queue'd item. as you queue things, it will guess at the level you'll be when you've executed the entire queue. this level will be used to "unlock" the skills you have recorded from the trainer and the window will color things appropriately based on the estimated level.
the biggest problem is that gw's pricing scheme isn't quite as automated as i'd like -- you have to manually jigger some things to see if it's cheaper. because a reagent might have multiple ways to generate it, the ideal path might include a mix of different techniques... it's actually pretty complicated when include things like milling and disenchanting...