Seen at AmmoToGo.com last week:

For the mathematically challenged, that works out to 6.8c per round for the LR, vs. 30c per round for the Mag.
This is decidedly not a knock against ATG, by the way — I buy ammo from them quite often — it’s just a sad reflection on the high cost of shooting the excellent .22 WinMag.
As Combat Controller put it to me a little while ago: “If .22 Mag was even double the cost of .22 LR, I’d shoot it more than LR, every single day of the week.”
Ditto.
I know why there’s such a vast gulf in prices between the two calibers, by the way; I just don’t like it.
Just FYI AMMO SEEK has 22 mag ammo at 20 cents per round
According to google, they are both made on the same production line, however there are significant changes that must be made in-between production runs. So manufacturers have to factor in volume, demand, and downtime required to shutdown .22lr production in order to make a short run of .22WMR. If .22WMR were more popular and people finally stopped hoarding .22lr, maybe we’d get some longer production runs and cheaper ammo.
Of course, shit in one hand and hope in the other, see which one weighs more.
I have a lever-action Winchester in .22WMR that I really should be shooting more often. Once it cools down a bit I’ll make some time.
Sounds like you have the 9422M. I have one too, very well made gun.