[JimC]

They're the same engines as the Cessna 340, so you can expect maintenance costs to be similar.

340s can cost upwards of $350,000 so owners aren't as surprised when they have a $25,000 annual.

337s often cost less than $100,000 so owners can be more surprised when an annual costs $25,000. (If a Rocket costs less than $100,000 it needs a lot of work!)

I've owned both a 340 and a 337. They each have their own uses. But don't expect one to cost less than the other.