also: めっけもの
noun
bargain; find; lucky discovery
Refers to something obtained at a great price or a serendipitous find, often with a sense of pleased surprise.
このバッグ、千円だったんだ。めっけもんだよ。
This bag was only 1,000 yen. What a bargain!
古本屋で珍しい本を見つけて、めっけもんだった。
I found a rare book at the used bookstore; it was a real find.
noun
unbelievable good luck; unexpected good fortune
Emphasizes the luck or fortune of a situation, not just the object; often used in exclamations.
雨が降る直前に洗濯物を取り込めて、めっけもんだった。
I managed to bring in the laundry just before it rained; that was unbelievably lucky.
掘り出し物 also means a great find or bargain, but it is more neutral in register and often used for tangible items discovered after searching. めっけもん is more colloquial and emphasizes the luck or surprise of the discovery.
Derived from the verb 見つける (みつける, 'to find') with a colloquial contraction and the nominalizing suffix もの/もん. The exact historical development is uncertain, but it likely originated in casual speech.