noun
worth; value; effect; result (that makes an effort worthwhile)
Refers to the worthwhile result, benefit, or satisfaction gained from an action or effort. Often used in the pattern 〜したかいがある (it's worth doing) or 〜したかいがない (it's not worth doing).
努力した甲斐があって、試験に合格した。
My efforts paid off and I passed the exam.
この本は読んだ甲斐があった。
This book was worth reading.
高いお金を払ったのに、全然甲斐がなかった。
Even though I paid a lot of money, it was completely worthless.
Rarely used kanji form.
The historical derivation is uncertain. The kanji 甲斐 is an ateji (phonetic) spelling, and the word is considered a native Japanese term.