Why doesn't it mean "the morning is cheap"?
I quite agree - presumably someone thinks you can't buy a morning. Why not!
Not quite what I meant. 'The morning is cheap', is another way of saying, 'in the morning it is cheap. However I have come across quite a few phrases in this course which make absolutely no sense, so this could well be another.
why not "Pe dimineata"?
Where is the preposition in this phrase?
What does this even mean? Do Romanian restaurants often have morning specials or something?