Creating Artifacts

[Ruethgar]

So apart from that one chapter in the Nether Scrolls(presumably) and a divine rank, is there any way to make an artifact? The one I'm thinking of (http://archive.wizards.com/default.asp?x=dnd/fw/20040919a) in particular essentially mimics Explosive Plant Growth, and Entangle, but has the distinction of creating flora not previously present which is what I would want. The text says that Dryad Druids make them, which isn't too much trouble. A Redheaded Dryad can leave their oak and adventure just fine and only have an ECL of 4(yay at will Entangle), but there are still no rules for the cost other than a living tree wiling to sacrifice herself to make the artifact. Would getting the ability on a Custom Prestige Race technically cost null since artifacts have null cost? What would be a more appropriate cost for creation?

[Psyren]

According to the text - "these objects are fantastically powerful and rare minor artifacts that dryad druids purportedly carved from the living hearts of trees who were willing to give up their existence to help create an object of great power to help protect the forest." So the dryads did create them, but the level of involvement from the trees, how many trees it took to make one of these, the length of time it took, how powerful the dryad druids were etc. are all open variables.

Therefore, unfortunately, both the RAW answer and the fluff answer to your question are the same - ask your DM. Artifacts cannot be created by PCs unless specifically stated otherwise, and this item has no specific exception to that rule.