Free: Contests & Raffles.
The .270 has a better flight path and will be more accurate at longer ranges.
If you already have a .270 Win, I'd suggest you get a .338 Win mag for a dedicated elk rifle.
...If you already have a .270 Win... I'd suggest you pocket the money you'd spend on another rifle... and use it for an out of state hunt... that way you could clobber two elk!