I'm wondering if the cost to masterwork an enlarged weapon doubles along with the extra cost to make the weapon larger. If someone could tell me what book to look in that would be great, the page number would be even better.
I don't think it would; the masterwork component is built and priced separately from items anyway, and weapons of differing sizes in the PHB, which are otherwise identical ( like longsword and greatsword ) have the same masterworking price.
