one man's treasure is another man's trash

What one sees as valuable, another would view as garbage or junk. Reversed form of "One man's trash is another man's treasure".

Peter: OMG, you have the Johnny Seven OMA Gun! That was the coolest toy ever as a kid.

John: Throw it out man. That thing is worthless, I kept losing all the ammo.

Peter: I guess one man's treasure is another man's trash.