Diablo 3 Auction House: How do I find only blacksmith recipes I can learn?
Solution 1:
No, unfortunately it is not possible now. Hopefully it will be possible in the future.
The only way to buy only blacksmith plans that you don't know is to make a list of all plans(here's the link that might help you) and then cross out the ones that you know. And then look for the ones that are not crossed out.