Where to start?First off you could have mounted a 40mm scope in low rings and been where you are now for far less,but seems ya have $$ to burn so go at it if it floats your boat. $700 ,dam your in Swarovski territory!So seeing as how money is flowing freely,purchase as many brands and type bullets as you can and then go to shooting them to see which your rifle spits out the best,as each has a mind of it's own and tastes will vary.As for the $$ in ammo it is bullet construction your paying for,as you stated a whitetail don't take much bullet but hit one with a cheap non premium at 270WSM speeds up close, catch shoulder and a bit of a mess may be on your hands.Accuracy would be my 1st concern,then bullet construction and if I just shelled out $700 + on a crooked scope a couple bucks for more expensive ammo wouldn't even factor in the equation.Good luck hope she shoots for ya