Kaito's now seeing diminishing returns on the experience he's getting from the monsters on floor 3, so he makes the decision to brave the floors beyond... totally unsuspecting of what he's about to find there.
You're kidding, right? 
This thing was expensive!
‫أنتِ تمزحين، صحيح؟ كان هذا الشيء باهظ الثمن!
Wie bitte?
Der war total teuer.
Lo dices en broma, ¿verdad?
¡Es carísimo!
Es coña, ¿verdad?
¡Me ha costado muchísimo!
Stai scherzando?
Mi è costata un occhio della testa!
Tá de brincadeira, né? Isto foi bem caro!
Гонишь! Я за него кучу денег отвалил!