Well i actually do like the crafting system in general. Does all it should, is not too fast or too slow, finally there is something to do with vendor trash, collectables have a use and so on...
But yeah using named loot (and partially very hard to aquire named loot) as materials is really not a great idea. Why just not stick to the collecatble idea... if something should be hard to make just let it cost 100 prayer beeds or whatever...