Meanings
The amount of money obtained or taken at one time appears to be very large.
Examples
・He made a killing on the stock market.
株でがっぽり儲ける。
・He is so busy lately. He must be raking in the dough.
彼は最近忙しい。がっぽりもうけているに違いない。
・No matter how much money they make, they will just take it all in taxes.
いくら稼いでも、どうせ税金でがっぽり取られるだけさ。
Dogmatic Opinion
“Gappori” is an expression strongly associated with money and has a strong image of “earning”.
The only thing that is “Gappori lost” or “Gappori taken” is taxes,
but the average person does not earn enough to be taxed heavily.
When taxes are taken out, it can be expressed as “Gossori” or “Gattsuri”,
so “Gappori” is still “to earn” or “to profit.”
Even if you win 600 million yen from gambling or playing the lottery,
not expressed as “Gappori”.
Although the expression does not refer to illicit earning, there is little respect for the way the money is earned or the person who earns it.
Rather, there is a somewhat skeptical eye.
The image of a new business or an irregular way of earning money, rather than from the main business that has been going on for a long time.
Therefore, no one calls himself “I’m making Gappori (a lot of) money.”
I wouldn’t say that Elon Musk is making Gappori (a lot of) money.
There may be “religious corporations are making Gappori (a lot of) money while receiving preferential tax treatment.
In essence, “Gappori” is described as “undeserved” when we feel that the large sums of money they are earning are not commensurate with the process and status of earning the money.
I would like to make a modest assertion.
Proximate Expression
make a killing
rake in big money
