thanks, please post more info. My wish is to hit at 5-600 meters. Scope opinions are welcome along with mounts.
What model is your Armalite? It MIGHT swing it with a 69+gr bullet. For optics at that range I would be with a good variable with a max power of between 18-24x.
For a bolt gun my best ever was a Howa, but I think the twist on it won't stabilize the bullet weight you will need out that far. In fact I think you might have a difficult time finding a bolt gun faster than 1/9 for this.
I would like to think you might swing it with a 1/9, but I am not sure on that. Since you are worried about price per round I would also think you are looking to succeed on a budget so here are my suggestions:
1. Handload you rounds. This way you can customize them to your rifle. You would be surprised at that range what a difference a little change in OAL will do for you. It will also keep ammo costs down.
2. Assuming you AR won't do it for you, consider a cheaper bolt gun with a good action. Several companies make such and any can be customized at your leisure. That way you can upgrade stock, barrel, trigger, and get any action work it MIGHT need done as your demands require.
3. Practice allot. I know my Howa claimed several 500yd+ kills, but that was because I was always at the range writing down notes and working on my form. Without that I would be the limitting factor.
4. Remember the law of diminishing returns. To explain in a clear way: a $250 1911 will shoot, a $450 one will be a huge step up, a $600 one another, but smaller, step up, a $900 one won't be noticable to the majority of shooters as better, and beyond that only a skilled shooter could tell improvements in them. My $250 Swift scope was as good as I ever needed and honestly I couldn't shoot any better with a $1000 scope.
Just a few inputs for you.