The cost of writing a spell in my spellbook

Question

I have seen from various online sources that it costs some gold to write a new spell in your spellbook from a scroll or other spellbook you've found.

The player's handbook only mentions that a wizard can do it at any time. I thought this meant the wizard had nothing else to do than spend the required time to write the spell. But those unofficial sources are contradicting this.

Is it true that there is a cost for writing a spell into your spellbook (on top of the eventual cost of buying the required scroll)? How much is it? And where do the rules say that?

Does this mean there is no way to learn additional spells (on top of the free spells at each level) other than spending a large amount of money?

Answer 1

Those unofficial sources are correct

The Player's Handbook on Writing a New Spell into a Spellbook says that

Once a wizard understands a new spell [from a scroll or another's wizard's spellbook], she can record it into her spellbook.

Time: The process takes 24 hours, regardless of the spell’s level.

Space in the Spellbook: A spell takes up one page of the spellbook per spell level, so a 2nd-level spell takes two pages, a 5th-level spell takes five pages, and so forth. Even a 0-level spell (cantrip) takes one page. A spellbook has one hundred pages.

Materials and Costs: Materials for writing the spell (special quills, inks, and other supplies) cost 100 gp per page.

Note that a wizard does not have to pay these costs in time or gold for the spells she gains for free at each new level. She simply adds these to her spellbook as part of her ongoing research. (179)

These aren't all the rules for doing so, and the entire process is pretty complex. I urge reading the Player's Handbook on Arcane Spells (177-9) to better understand the wizard's adding-spells-to-a-spellbook mechanics. (There's also a summary at the beginning of this answer.)

A wizard can prepare spells from another wizard's spellbook without transcribing the spells into his own spellbook

This is nominally free if the spellbook's already been liberated from another wizard. Doing so requires a Spellcraft skill check (DC 15 + spell level) per spell (Player's Handbook 82-3)

Answer 2

The cost of writing a spell into a spell book is 100 gp per spell level. This can be found under "Writing a New Spell into a Spellbook", Player's Handbook page 179, or on the SRD.

Space in the Spellbook A spell takes up one page of the spellbook per spell level. Even a 0-level spell (cantrip) takes one page. A spellbook has one hundred pages.

Materials and Costs Materials for writing the spell cost 100 gp per page.

The transscription cost does not need to be prohibitive. See the question: How does a Wizard achieve a very cheap spellbook full of spells?