Refers to something unexpectedly good obtained with little effort or cost, like a great deal or a stroke of luck.
This vase was only 100 yen. It's a real bargain.
It started raining, but I found an umbrella just lying there. What a godsend.
Standard kanji spelling.
Kana spelling is common in casual writing.
Mixed kana-kanji spelling, less common but still used.
Abbreviated kanji spelling, rarely used.
Compound of 儲け (もうけ, 'profit, gain') and 物 (もの, 'thing'). The exact historical derivation is uncertain, but the word has been used since at least the Edo period to mean a lucky or profitable acquisition.