I am working on the legendary crafting quest now. One suggestion for anyone is that they invest in gardening. The tough reagents for this quest are Sunstone, Aether, and Fossils. Golden pearls are not as difficult to find and can be purchased for good price if you wait in the bazaar. Fossils will usually go for 1000 gold per unless you get lucky and there is a huge dump of the reagent on the market.
Gardening is by far the most efficient method to obtain the most difficult reagents. Maelstrom Snapdragons and Fickle Pickles will drop Aether and Sunstones as potential reagent rewards. King Parsley and Evil Magma Peas also drop the reagents but they are only available as drops or purchase through the crown store. My suggestion, and strategy for my next wizard when I roll one, is to level your gardening early and focus on Fickle Pickles. They only require a small enchanted plot and you can buy them in the bazaar cheaper than you can in Golem Court. The small plot size allows you to create a large space where you can use large area of effect gardening spells for maximum advantage. While this may seem expensive consider that you are almost certain to gain seeds for some of the plants if you grown them through their entire life cycle. Over time you will acquire a number of rare reagents. I doubt you will gain all that is needed but you will make a significantly reduce the required reagent need.
Sunstone isn't difficult to get, just tedious. Same for Fossils and Aether. If you farm Stone Blocks in Stone Town in Zafaria you will get enough to Transmute Sandstone then Transmute Sunstone. Yes, you need a lot of Stone Blocks, but you can pick up 10 or 12 easily each time through Stone Town, plus there are occasional bonus drops of Fossil, Sandstone and even Sunstone (you can also sometimes find Sandstone on its own there).
Aether can be transmuted from Kelp, which you can easily farm in any underwater area, especially Crab Alley and Crustacean Empire in Celestia. Aether also shows up all the time in the Bazaar - I saw 225 of it for sale there once.
My advice is pick up every reagent you see in your travels, you never know when it will come in handy. Think Cat Tails aren't worth it? Wait until you need Water Lilies - you can transmute them from Cat Tails. Even lowly Mist Wood is used in several transmutes.