shimmerfly, Henroo, Zoof, I wonder what you really think about the Moonstone Library set? I just entered Sorcerers and Dragons and have had my set up about a month. Is it a keeper?
At the very minimum, keep the Gum Tree and Mana Plant and upgrade those as needed. At and past the 5th chapter, they can be used to fulfill those "Upgrade lv 5 or higher" event quests for dirt cheap. Once you can dedicate the space for the whole set in your city, you'll never go back. It's a bit slow to begin with, but those daily spell fragments and combining catalysts really do add up, allowing you to free up production in your Magic Academy* for something else, such as Power of Provision spells. It can get a bit expensive to keep the Moonstone Library Set current to your chapter, but so long as you only have one set, you can pull certain shenanigans** since level doesn't affect how many SFs or CCs you get.
* IMHO, the free diamonds you get from Spire and other sources are best spent getting Magic Academy up to level 5 ASAP. As long as you keep your tournament game strong, you'll effectively never run out of relics even at the vastly improved craft speed.
** In my main city, I allowed the main Moonstone Library building (4x4) sit out of date by about three or four chapters. It'd have been stupidly expensive to burn that many Royal Restorations. Since I only have one set total, I sold off the building and waited for it to reappear in the Magic Academy*** at the current chapter. I had about 200CCs and 200K SFs saved up before attempting this and my stockpile didn't diminish too much while I waited. It took me about 3 weeks for it to reappear, though I also burned about 20 Sips of Clarity (for unrelated reasons) during that time.
*** This trick only works if, after having sold off the building, no instances of that building exists either or both in your city
and your inventory. For those who were around and actively running Spire when the Spire was popping out Moonstone Library Set pieces like it was going out of style, they're out of luck on that front.