In English, the verb "buy" can be used to refer to somebody's having been killed, usually in the past tense; for example:
Harry bought it in World War 2.
Where does this phrase come from?
I think it may derive from the idiom: bought the farm:
To die, particularly in an accident or military action.
The origin of this phrase is uncertain. It is 20th century and all the early references to it relate to the US military. The New York Times Magazine, March 1954, had a related phrase, in a glossary of jet pilots' slang:
"Bought a plot, had a fatal crash."
That clearly refers to a burial plot. The 'bought' in that case probably doesn't suggest any actual or potential purchase, but to an earlier use of 'bought', that is, being killed. This dates back to at least the early 20th century. This example from 1943 isn't the earliest, but it does make the meaning explicit. It's from Cyril Ward-Jackson's It's a piece of cake; or, R.A.F. slang made easy: