Meaning of “to trade somebody in”

Question

The first verse of the song Take Back The Instant by General Elektriks is the following:

Take back the instant

When you brushed him off your shirt

You tried to drag him to the trash

You tried to trade him in for cash

The lyrics as I understand them are about distribution of wealth, and how some people are born lucky and grow up to take everything for granted. The first verse is in line with that, but I don't understand the last line: what does trade somebody in mean?

My first thought was that it was a similar construct as "show somebody in", and so it meant invite somebody into a deal. Could the line be rewritten as "You tried to make a deal with him to extort his money"?

Source of the lyrics: genius.com

Answer 1

This is the phrasal verb to trade in.

It means, roughly, to exchange to a vendor for cash so that you can get something better or newer from the vendor. For example, Should I Trade my Old Car In or Sell it Privately?

So basically the lyrics mean "you tried to exchange him for cash (presumably so you could get something else)".