Well, any craft can be as complex or as simple as you want to make it. For instance, in RL I have been an apprentice blacksmith for the last 3-4 years (off and on). \'Smithing (especially in a fantasy setting with all its possibly exotic materials) can be made extremely complicated if the author wants to take into account metals, alloys, forging methods, tempering, etc. Each step in the forging could alter properties ofd the blade (sharpness/damage, how it keeps it edge, hardness/hp of item, etc.)
Other skills can go on the same way, from baking to basket weaving. I guess my point is I am wondering what level people would want. Perhaps a two sided system: You either chose to let the game decide (ie I just want a damn sword, tell me what I need) or you chose the individual methods (Here\'s what I have, here\'s my skill, what do I get?) to get the result you want. More expensive processes (different ores, forges, tempering agents, etc) could work as effective gold sinks. This would also create a more diverse player made item market.