Out of a bar close to Termini station I saw a notice showing the offer "Italian breakfast: cappuccino + croissant + orange juice, 6 euros" (in English).
Anybody who has some experience of Rome knows that on the average a cappuccino costs 1 euro or a bit more, a croissant .70-.80 euros, and an orange juice some 2 euros. I think, even in this bar, three customers ordering separately these three things would pay some 4 euros.
So, I suggest not to trust so much these "offers", especially if they are written in English (a "real" offer should be addressed to local people too).
By the way: the real "Italian breakfast" usually consists of cappuccino and croissant, without orange juice (drinking milk and orange juice in the same meal may even have harmful effects).