My first question is why does she want to change? What does she feel the "upgrade" is going to gain her in realistic terms? Both carry enough energy to kill out to at least 300 yards, with the 08 having a bit more on paper but the 243 shoots flatter and will most likely have less recoil.

I mean if you can afford it and she just wants another gun then by all means go for it, I would never stand in the way of someone getting another toy. However if you really can't afford it, and she shoots the one she has well you probably won't gain much by switching to something that close to what you already have. I don't believe an extra 400 ft/lbs or so of energy from 100 to 300 yards is going to equate the animal being anymore dead than it would have been with the 243.

Only my opinion though, just thought I would give you something to chew on.

Paul