After hearing that you think you will probably end up hunting eventually.....and hearing that you don't mind spending a little more on ammo right now..and knowing that you already own shotguns and no rifles......here's my advice.....
Buy 2 used rifles........rifle #1 a decent .22 caliber bolt action
.........rifle #2 a decent .308 bolt action IN THE SAME MAKE AND STYLE AS THE .22

This will give you the opportunity to go the range and shoot the .22 a ton cheaply....and the feel and practice of working the bolt and settling in to the similar stock (if you can get that to happen) will make you a better shooter. Then, the 308 will allow you to hunt many species, and the cost of the ammo is comparable to the venerable 30/06 with a little less recoil and a shorter action.
(But you should still get a 30/06 someday!)