I discovered a video from A1 Auto showing how the job is done. I can see where someone who's not used to wrenching could be intimidated by the job. IMO, it's overly complicated for what is essentially an economy car. It's far more complicated and time-consuming than my Camry, for example, and I wouldn't care to do it in my driveway.
Sure, everyone has different skill levels and abilities, but IMO changing plugs on so simple an engine should be a lot simpler, and a lot less expensive if having a shop do the work. Going by rates in my area, just the labor for changing the plugs, if using the book rate quoted by
@The Critic, would be $225.00 to $280.00 + gaskets and plugs By comparison, the shop charge on my Camry would have been about half that.