Depends. Not always.

But there is this one shop selling shawarma sandwich made to fresh bread that costs 3.90€. And that is already a good lunch.

A döner sandwich can cost 2.90€ the cheapest.

Bakeries have baguettes with cheese and ham for 4-5 euros.

If you go to Mitte, a döner can already be 6-9 euros. And that is expensive.

^ In America, you have to remember that we overpay for crappier food.