The restaurant decided to set the prices according to each other customer.
I got ripped off
I was overcharged
客を見て値段を決める=The restaurant decided to set the prices according to each customer.
set the prices=値段を決める、つける
according to each customer=それぞれの客に(よって)〜
ぼったくられた=
I got ripped off (とてもカジュアルな言い方です。ぼったくられた〜のニュアンスに合っていると思います)
I was overcharged by the restaurant (こちらは普通な言い方です)
overcharged=高過ぎる値段を付ける
ご参考になれば幸いです。