Within it's range, the 17 HMR seems to be a much better killer of small varmints than most 22lr. It also has the edge on accuracy in most cases. Much safer to use for critter control where the 22 might ricochet.
I've used the 17HMR to dispose of groundhogs and raccoons in places I would not have used the 22lr simply because of the greatly reduced chance of pass through and/or ricochet.
I don't consider the 17 to be a 200 yard varmint round since it is losing it's goody by that range and is subject to wind drift. That tiny bullet has only one thing going for it and that's velocity. W/o speed the performance is less than exciting. This is just my opinion and I'm sure someone will post that they killed something or other at OMG range with their 17 and can do that every time they go hunting.
As for the cost of ammo, I wouldn't be shooting mine much at $20/box. I can shoot a 223 for just a little more than that but I suppose your 223 prices are proportionately higher,too. You're in the US, right? Those brown trucks deliver ammo lots cheaper than the Walmart trucks do.