US Prices

Appetizer (starter) - 4usd
Entree (main) - 6usd
Drink - 2usd
+tax (10%)
+gratuity/tip (15-20%)

You pay at least 15usd.

The gratuity in the usa is not a choice (unless you have an horrible experience), but a mandatory part to add to the bill (before taxes). The waiters are taxed on their salary plus expected 15% taxes! So if you don't pay gratuity they will be taxes anyway, their salaries are very low already counting they will receive good part of it in tips.

But usually, here in the usa, only the waiter for your table will be nice to you (hey, how are you today?/everything alright? three times during the meal). When you leave the restaurant no other waiter will say 'goodbye' or 'thanks' to you. You don't see either team work. Also you see that waiters share the tables among them, so that each gets same amount of costumers. Discussions continue and continue about the advantages or not of tipping system, but I just feel there are none. In my opinion (knowing it is not easy) they should fight for correct base salaries and having tips just as an extra and purely in discretion of the client. More, it is much nicer when any other waiter thanks you for coming, no matter if he received your tip or not.

Well, not necessary the simultaneous 'thank you' by every single waiter and cook that you have in Japan or South Korea (quite amazing). :-)