Get a 2017 with less miles. Exact same as the 2018. My 2017 with almost 40k miles has been perfect. Just oil changes and a set of tires. Not a single issue. Got 2 buddies with 2017’s as well. No issues.
My AG ‘17 has been bulletproof as well. Hard worker and absolutely zero problems. That number for the high mile ‘18 seems a bit much—if financing, you’ll get a much better rate on new too which would eat up a lot of the difference. Good luck.