I recently got this recipe (Elixir of the Searching Eye) for cheap, namely 10g. To make a long story short, a guy offered it on /2, I asked him how much he wanted, he replied "make an offer", I replied that it was just for the completeness of my collection of alchemy recipes (since the recipe doesn't seem to be all that useful), he said 10g, deal.
Then I decided to check here the kind of price this potion would sell for and read the discussion for this item to see if it has any kind of use that I didn't think of. And then I realised that this recipe can apparently fetch 150-200g at the AH.
Now my question is: should I learn it, even though I might never use it, but simply because I want to know all the recipes and becuase I might need it someday? Or should I put it on the AH and get a free 150g?
What do you do in these cases?