PC Max Damage Fiery Longbow 15^50% OR Weap + Bow String

As title says i want to know a PC on Fiery Longbow 15^50% or for the Bow (non collector version) + the Bowstring separate.

need req.. and the string is worth mabye 500-1000 gold

~ Req 10 or less

Im a noob tho, approximatley how much would the Req of the weapon change the price of the weapon?