Am I Being Unreasonable? Original Owner Wants Car Back

I had to chuckle at this. One of my personal sayings is that if you think you paid too much for something you really wanted, in six months it'll seem about right, and in a year it'll be one of the best deals you ever made. Sometimes the money is irrelevant.
Like Ross Johnson, former CEO of RJR Nabisco said, "a few million dollars are lost in the sands of time." He was a sneaky greedy crook, but he got the concept