The tune is somewhat harsh, it is meant to be. In my opinion the way alloying
had been tuned (in recent year or so?) made materials that can only be alloyed
far too common. The purpose of this tune is to make them more rare and to
also cut down on abuses that essentially allowed a crafty merchant to turn any
quantity of materials into a large chunk of another material pretty much at
will.

Additionally, the ability to alloy more than 2 mats was added to provide extra
combo's and complexity; it was not added so that people could alloy 10
different materials just to ensure they get the remaining 1 material of that
category. You can still do that now of course, but I believe you will find it
is not worth the effort.