My point isn't about the cost to make the gun. It is about market conditions.
The first firearm many, many people shoot is a 22lr. You might say it's the gateway gun into a life long hobby of hunting and/or shooting. Gun manufacturers know this, and they probably know that if they make .22s too expensive for the average joe, that joe may not go on to buy centerfire rifles, shotguns, or handguns down the road.
So from a marketing standpoint, I think manufacturers such as Ruger, Marlin, Remington, Savage, and Mossberg would be hurting themselves if they jacked rimfire prices up too much.