I asked a coworker who lives their part time for some cheap recommendations but everything she sent me is above your price range, though short of fast food options I don't know that I've ever had breakfast in a restaurant for $6/person with drink.
Keep in mind as well that sales tax is 8.25-8.75% depending on which town you happen to be in.
She said there are lots of good taquerias and thai/vietnamese places that are pretty good and very cheap but she doesn't actually know their names.
First Awakenings is very good for breakfast/lunch but is closer to your dinner number.