Many wizards I know have expressed that they have given up on crafting due to the extreme unavailability of the reagents needed, and the tediousness of trying to find them. I have a few ideas to help with crafting and make it less frustrating and more fun:
Create bosses for wizards to farm that drop only regents for crafting. I would imagine it should be a solo golem type tower with many levels, the harder the bad guy the more rare the reagents they drop.
Examples: A junkyard boss that drops scrap iron, springs, blocks, and leather straps. A jewel thief or gnome boss that drops gems, diamonds, black pearls, and other rare stones. A nature boss that drops that drops flowers and plants. A mad scientist boss that drops vials, parchments, scrolls etc. A card shark that drops only treasure cards. (This may also help with all the card beggars I see every day)
Another idea would be to give wizards the ability to grow or make reagents in their home. Maybe create garden plots and buyable seeds. Give each one a timeframe like crafting slots to harvest, but make it worthwhile.
I also reagents should be tradable via the shared bank.
These kinds of things would make crafting more available, fun, and useable for everyone!
I really like your idea for the tower! It would be so much better to know where to go to get them rather than wandering around aimlessly hoping to come across one!