If you aren't an instructor do you have to sit through the entire course every two years, or are there generally accelerated ones for MDs? Because if I have to waste another day sitting through ACLS lectures with people who have never taken the course I might scream.
For the AHA classes, you can usually do a renewal course that's ~6-8 hours long (on paper anyway), take your practical and written exams again, and you're good to go for another 2 years. As long as you don't let your cards expire, you don't need to retake the full course ever again.
If you are an instructor, you have to teach 2 classes every 2 years, and you still have to sit through an instructor renewal course every 2 years.
To the OP, I was an instructor in the AHA merit badges when I was a paramedic, and I taught at a medium-sized regional hospital. The instructors I taught with were paramedics and nurses for whom teaching was a second job. I knew 1 or 2 attendings who helped teach because they liked teaching, not because of what it paid (~$30/hr).
Some of the residents told me they made $3 to 4 grand a weekend covering rural hospitals and ER's in the surrounding area, by comparison. Given that option, I wouldn't have bothered teaching ACLS, either.