30 acres at .75 gal x $3 x 14 days = $945 savings.  It was fast math??  You still saving fuel just how much?

You already said it SAVES fuel.  you never said how fast a payback you required!!!!!  It WILL pay itself in just fuel, maybe not in 3 years but it will.

I think 3 foot overlap on 35 foot is very common don't you??

Lets see your math?  how much overlap on your wide equipment before autosteer??