I love when people try to rationalize this stuff by comparing it to completely unrelated items and their subjective worth. I think of it more like this, say I went to McDonalds and bought a $5 meal but if I want extra pickles it'll cost me another $2.50. Sure the DLC isn't that much but given how much the base game was and the content provided, the worth just isn't there, not with Destiny DLC.