I would go with the Sako. And would not consider a short mag in Tikka. With their one size fits all action there is no advantage in action length over convential calibers. You would just be shooting ammo that cost twice as much
Are you saying that Short mag ammo costs 2x what regular ammo costs or the belted magnum ammo it competes with? Look at prices and compare apple with apple and tell me how much difference there is.