What is the meaning of the phrase one man's trash is one man's treasure?

One man's trash is another man's treasure.

Obviously, It is a proverb.
WHO is the question though, not WHAT

Therefore the known correct answers are:

Norman Percevel Rockwell in The Saturday evening post: Vol 198 (1925), but William & Robert Chambers Journal of popular literature, science and arts (1879) has

...as one man's meat is another man's poison, so one man's rubbish is another man's treasure.