Problem:
Increase target farming for specific items slightly.
Add another Dungeon.
Idea:
A player can find Blueprints for any unique item or set items.
To craft a unique item from a blueprint one needs specific materials. (And maybe a smith)
These materials can be attained through completing a new Dungeon Successfully.
One gets 1 to 4 random materials upon completing the dungeon, depending on the difficulty.
For a unique shield, one might need 7 shield shards for example. Or leather / metal / etc.
Limitations:
Crafted Uniques cannot have Legendary Potential.
Crafted Uniques always have one stat which will be at the minimum.
Self-find will therefore always have more potential.
Conclusion:
Even if somebody finds a Blueprint of a rare unique item, that one needs,
one still needs to farm specific shards for it.
Additional Thoughts:
On a first Sight: Blueprints should be able to be traded publicly without harming droprates or creating a trade-focused economy.