when you said "the moon is pretty cheap" did you mean cheap as in stingy or cheap as in inexpensive? if it is the latter then how expensive precisely is the moon?
actually what was cheap is that line. the line was going to be "the moon is made of keys but i just changed them."  with some interesting chords for 'just changed them'. this made sense, and seemed to tie together with one of the clear actual themes of the song. but after writing it i woke up the next day in a rage of panic, and felt that that line was too.......... expensive