He acts super friendly toward you, acting like you're his best friend & saying things whenever you run into each other like "I was just thinking about you!" & "we must have been married in a past life!" But 1. He charges you more for arrows than every other merchant in the game 2. Whenever you have a beetle in your inventory he stops the conversation before you can buy anything from him to ask you for it for his collection, & if you say yes he trades you a crappy tonic but if you say no he suddenly turns on you and essentially calls you a bad person. Then of course the next time you talk to him he acts friendly toward you again like nothing ever happened. And 3. When you get the final armor for finding all of the shrines, it turns out in order to upgrade it all the way you need a whole bunch of the rare beetles this false friend has been fleecing you for the entire game. So he acts friendly, but it's all a front to charge you extra for necessities and manipulate you into feeding his beetle addiction, and the second you displease him he acts hurt, turns mean, calls YOU the bad person, & then "forgives" you and reassumes the friendly facade all to condition you into wanting to keep him happy. And then it turns out all of this effort on his part was some kind of sick long con to screw you over at the very end of the game. Beedle is an abuser, an emotional manipulator and not your friend.