Bastion and Beyond
You can create a scroll of any spell that you know. Scribing a scroll takes one day for each 1,000 gp in its base price. The base price of a scroll is its spell level × its caster level × 25 gp. To scribe a scroll, you must spend 1/25 of this base price in XP and use up raw materials costing one-half of this base price.
In lieu of XP, stars are used to pay costs, rounded to the nearest star (possible zero stars). If multiple scrolls are created in between adventures, the costs are added and rounded to the nearest star (1 star=200 XP).
Any scroll that stores a spell with a costly material component or an XP cost also carries a commensurate cost. In addition to the costs derived from the base price, you must expend the material component or pay the XP when scribing the scroll.