Opposite food

Went to eat Vietnamese food last night. There was a great deal, at least at the time where it was a 30 dollar course dinner set. I read the menu items and it looked like a great bargain for dinner for two. The food was honestly quite good, and one of the best Vietnamese food that I have tried in Tokyo thus far. Even though I had a great deal, I didn't go overboard in ordering drinks, actually I only ordered Vietnamese ice coffee (which was more like Cafe au lait) and tea. Come time to paying the bill, I had my 30 something dollars at hand but the cash register had other plans. It flashed out a gentle green colored 71 dollars equivalent on the screen. I was shocked. It turns out the dinner set was 30 dollars PER PERSON. We questioned the clerk about the price and even though the price did not say 30 dollars per group, it didn't say per person either. The whole time I was expecting something almost half that price, so my fingers felt ashamed when it had to go fetch ichiman yen (100 dollar equivalent) bill for Vietnamese food. Coming from the D.C. area, Vietnamese food was always known as "cheap eats" while Japanese food was known as the most expensive out of the Asian cuisines. It really feels weird that it is now opposite here in Japan.