I understand what you're looking for, and agree it'd be a cool feature.
However, I think it'd be better to just do something like this in a "free text restriction." In a FTR, you just type in how you want the link to be restricted. For example ...
((HEALTH < 24) AND (STRENGTH < DEFENCE)) OR (MONEY>100) OR (HASITEM(224))
So basically, the link would be displayed if ...
you have item #224 (this would require the author to look up the ItemID, which would be exposed on the Item Page)
--- or ---
you have more than 100 money
--- or ---
your health is below 24 and your strength is less than your defence
Make sense?