I'm sure that Abraham was overjoyed at the thought of killing his only remaining heir, that meant nothing to people in those times. *eye roll*
Oh, man, I think we're safe in assuming that Isaac meant something to Abraham or it wouldn't have been a "sacrifice". It's inherent in the word sacrifice that it means giving something of value!
The whole point of the Abraham Isaac thing is that it wasn't the sacrifice that God wanted, he wanted to be listened to in the sense of listening and obeying. It was always about listening to God.
I mean, he only had to tell the Jews that a thousand times in a thousand different ways before they never got it!
The whole meaning of sacrifice for sin was to show that it was rather pointless as to actually fixing anything about being just a dumb old human being. The giving up of something of value only meant anything to humans, God is a divine being on a non material plane, what does he need with a dead sheep?