I wonder if there's a translation issue on the Wiki???
Are you referring to the statement: "This is a
Common item, a frequent drop or obtainable from merchants." Note the use of the word "or." The term "common item" means it's a frequent drop, -OR- obtainable from merchants. It's a classification of a level of rarity, not list of places to get it.
Wiki page for Exlixer of Galade is
here.