I don't understand Discourses 4.3

The first paragraph is what im confused with.
[1] “The question that should be in the forefront of your mind whenever you relinquish an external object is: what are you getting in exchange for it? If what you get is worth more, never think that you lost out. [2] You wouldn’t think that if you got a horse in exchange for a donkey, an ox in exchange for a sheep, a favorable outcome in exchange for a bit of cash, decorous quiet instead of pointless talk, self-respect instead of lewd talk. [3] If you keep this in mind whatever your circumstances, you’ll preserve your character as it ought to be. Otherwise, I think you should realize that your time is being wasted and that you’re in danger of squandering and ruining all the work you’re currently putting in on yourself."

He mentions "If what you get is worth more, never think you lost out".

I don't understand. If someone received something that was worth more, why would anyone ever think they "lost out"? Wouldn't it be the opposite? Wouldn't you feel content exchanging something that is better?