Tiberius said:
It's easily worth the cost of the Book to a) get rid of that weight and b) not have to worry about losing all of my spells should something catastrophic happen.
This reminded me of something. IMC, we were arguing about the BBB... we've been using the non-Monte interpretation (i.e., it still costs to scribe); it's a high-level campaign, and the ability to let Wizards get completely around the scribing costs was just too much. This was when one of my players came up with a beautiful compromise:
The BBB isn't a spellbook. It's a template. That is, it's a magical conduit connected to up to 5 spellbooks you have stored in a secure location. They're the true magical books, while the BBB just allows you to use a normal-ink duplicate to memorize the spells.
So, when you get a new spell, you scribe it into your normal books, at the full cost and normal number of pages. Then, stick the spellbook in your home.
Okay, now that spell is available for the BBB to use. Copy the spell in normal ink into the BBB, and now you only need to carry the BBB with you to use the spell.
If you want to change which spells are in there, rip up the BBB page and a new blank one magically replaces it, but you can only copy the spell into the BBB if the original is in front of you (no changing it while you're in a dungeon).
The idea is, a Wizard might only ever need to carry one or two of these books (45 spells goes a LONG way), instead of lugging around a bunch of spellbooks. And, if the BBB is destroyed or stolen, you still have the originals at home. That sort of benefit is easily worth 9k.
One downside: you can't actually scribe a new spell into the BBB; first, you need to scribe into your originals. This isn't always practical, so a lot of Wizards will bring along a half-empty normal tome of miscellaneous spells, with room to scribe new stuff.
We added a few other things: the BBB only works if the originals aren't moved and only if they belong to the caster, so if you loot a BBB off someone you can't use any of the spells contained inside (you'll just have to rip out all the pages, and start over). Likewise, if the originals are stolen you can't cast the spell from the book until you recover it. So, a lot of "mage guilds" have vaults where members keep their tomes.
I'm sure he got the idea from the W&H library in the season finale of Angel, it had been on the night before. But it was a great idea, and it solved some DM headaches (loot off enemy Wizards, why join a mage guild, etc.)
Oh, and using the same concept, we also made Boccob's Blessed Scroll. It duplicates 10 existing scrolls, and when you read a spell off of it, both the original and that section of the BBS go blank. No more fumbling through packs looking for the right scroll; it's great for classes like Rogue that can't cast themselves but use scrolls often.