If you’re happy.... we’re happy. It makes no difference what you chose to pay for it..... if you decided at the time it was an equitable purchase.... then it was. Don’t let anyone tell you differently.
I learned a long time ago to stop asking questions about price once I'd paid. I did that once and learned I didn't get a good deal, and I would have been happier not knowing. You've already bought it, it's a great deal because it's a tractor and you're driving it.