I own rifles in both chamberings. I shoot both calibers well, and wouldn't feel handicapped with either choice afield. Both serve admirably well, and "real world" experience doesn't favor one over the other, unless you exercise an active persuit in marksmanship.
If you are (or become) serious enough to notice the differences, then you will end up making a decision based not on the relatively small increase in cost per-round, but the subtle yet worthwhile little gains in ballistics. Chances are good that by then, you will handload, and find the .260 to be even more frugal to shoot than the .308.
Talks about advantages of one caliber over the other, when fired at distance, should only be held after gaining competency at that distance. We all enjoy debating the virtues of one over the other, but very few of us have the personal experience to base our arguements upon.
Be honest with yourself... consider what you will actually use the rifle for, how often and how far you will really be shooting, then take your pick. Both are great choices, and you will be convinced that you made the perfect choice, or you'll end up owning and shootin them both. Either way, you win.
Ah, the old just because it can will you be able to argument. Rationale, real world applications and sensibility have no place here.
There are quite a few people in here I'm sure that have long distance experience and do quite well. However, a practical chambering such as the .308 would serve the majority so much better. There's a whole lot of difference in a quality repeatable set up for distance than the off the shelf rifle and scope available to most budgets.