Is ink so expensive 墨水很贵吗

Son: Is ink so very expensive, father?   Father: Why, son, what makes you think so?   Son: W...well. Mother seems quite disturbed because I spilled some on the carpet.   儿子：爸爸，墨水很贵吗？   父亲：不贵呀，你为什么这么想？   儿子：哦，我把墨水洒了一点在地毯上，妈妈好象挺着急的。