Consider the 10 pages required for the "Book on Fireball". Some pages are rare. Some are so common that people don't even bother collecting them when they drop. So how about we create a new Synthesis Recipe. Combine any three Fireball pages. If the synthesis is successful, we get a different Fireball page. That is, if we successfully combine 3 copies of page 1, we get a random selection from pages 2 to 10. If we successfully combine pages 1, 2 and 3, we get a random selection from pages from 4 to 10. This would give some incentive to pick up the common pages when they drop.
The same idea can be applied to all skill collection books: Fireball, Ice Spear, Thunder, Arrow Revolver and Shock.
It could also apply to other collections such as Dorcha Crystals. The Second Dorcha Crystal seems way more common than all the others. It would be nice to be able to get rid of my worthless multiple copies of the Second Dorcha Crystal by combining them for a chance to get one of the rarer Dorcha Crystals.
The idea can also apply to armor sets with bonus stats.
As an example, consider the Female Bohemian Armor Set. There's armor, hat, glove (band) and shoes. Each contributes 0 to 3 points to Magnum Shot Enhancement and 0 to 3 points to Support Shot Enhancement. However, you need to accumulate at least 10 points to an Enhancement before it has effect. So if we get Bohemian Shoes with bonus stats of 0 and 3, (0 on Magnum Shot and 3 on support shot), they're not very useful, since even if we get 3 points for Magnum Shot from each of the armor, gloves and hat, we'll still don't reach the minimum of 10 points. My experience is that we should should sell these shoes to an NPC, since we're unlikely to be able to sell them for a better price in the Auction House. In fact, it even seems to be a waste of time to try sell shoes with 1 point for either stat, since they only generate a bonus if they are worn with 3 other pieces each of which has the maximum of 3 points. No one seems to want to buy anything with less than 2 points on both stats.
So my proposal is that we can synthesis 3 pairs of Bohemian Shoes. If successful, the bonus stats are the sum of the stats on the 3 combined pairs of shoes. This can give higher stats than currently available maximum of 3 points.
For example, consider 3 pairs of Bohemian Shoes with stats of (0 and 3), (3 and 0), (1 and 2). Currently I'd sell these to the nearest NPC since they're near to worthless. Under what I'm proposing, if I successfully combine these with Synthesis, I get Bohemian Shoes with stats of 4 and 5.