most of the crafting professions are that way. You have to buy 375+ rare/exotic inscriptions from the same folks who sell crafting supplies. It's on one of the tabs along the side. Some of these inscriptions are cross profession as well, so you don't need to buy them for each profession. Weapon crafting seems to share a set, and armor crafting seems to share another set.
As far as ectoplasm is concerned, yeah it is a pain that the price has been rising steadily since last year, but salvaging rares is usually the way to go. Or check the trade post often and maybe you'll catch them at a lull. Also don't forget that if you happen to make a particular item to gain exp that you can't otherwise use, you can salvage it yourself and have a chance of recovering the ectos used for it.
pure discovery is usually the quickest way to level up a crafting profession. Each inscription counts as a separate discovery, so for example discovering a might sword, precision sword, vitality sword, toughness sword, etc. will net you more exp than finding a low material item and making tons of them.