I do a lot of varmit hunting here in Ontario, I use a Win Model 70 .243 heavy barrel, my friend uses a CZ .22-250 and my brother has a Savage .223, all are good for varmint hunting and we reload all. I have shot them all and the felt recoil on all of them are minimal.
The bigger the caliber the larger the range of bullet sizes there are and the cost is relative as well, really depends on the type of varmint, the expected distances you will be shooting and how pin point you want to be.
Generally factory varmint ammo, like Hornady ballistic tipped, among others works great. If you really want to be precise reloading is the way to go, allows you to experiment with different size bullets and powders to find the combo that your gun likes the best.
You cant go wrong with any of them, they are all very well proven calibers.
Scott