Hello!
So as long as I've been playing I have been told that to calculate weapon costs you calculate the cost of the weapon based on the material desired (ex. 4 RM simple weapon x 4 to make silver = 16RM silver dagger) and then calculate the quality (16RM silver dagger x 10 to make legendary = 160 RM legendary silver dagger).
However, recently some people have been trying to convince me that it would in fact be 4RM x 14 (14 being the cost of silver + the cost of legendary) which is only 56RM. I would dearly like to put this to rest.
Some rulebook quotes:
"Iron or Silvering a Weapon
The most basic smithing techniques will teach a young Blacksmith the art of crafting weapons from iron and silver. Iron weapons cost 150% of the original Raw Material (RM) values to make and require the entire striking surface to be made entirely of iron to be able to call for iron damage. Crafting silver weapons requires 400% of the original RM cost. A weapon may be either iron or silver, not both and must be done at the time of the weapon’s creation."
"Legendary Crafting
The Blacksmith has obtained a legendary knowledge of their craft. They are the foremost specialist their field and are considered an absolute authority in all matters of Blacksmithing. A Legendary Blacksmith can create items of Legendary forging, giving the item properties of an almost magical nature. Legendary weapons and armour are immune to effects which will permanently destroy them. The creation of legendary armour and weapons will cost the smith 1000% of the original Raw Material value. Please note that Legendary Shields are exempt to the above cost. All Legendary shields cost 200 RM to produce."
Doctor Ori Moran: A purple feathered Avian with a large shield. Paladin of Cassandra, Befriender of Villains, Committer of Treason and local Duck Enthusiast.
Nelinha: A wandering Ice Elf that can sometimes be seen around Ralinwood. Carries very little on her person save for a sword and small shield. Might be in a cult.
OOG: Alex H. - Ralinwood NPL, Jericho 2020 Narrator
The first option is correct. The costs are multiplicative, not additive.