My best money spent on a rifle was in fact spent on a pistol. When I was 12, I saved all my money from selling prairie dog hunter's fired 223 brass - and bought a 10" barreled Ruger MK II. It's really, really accurate. I've put God knows how many thousands of rounds through it, and killed prairie dogs at ranges that you wouldn't believe if I told you.

Rimfires are where it's at in the cost per use generated category.