Re: new to scopes need advise..
Assembling a rifle/scope combo for a grand that will shoot acceptably well and take big big game from 100 to 300 yards is not easy, but it's doable.
Having a rig built that will be durable, sufficiently accurate from 300 to 1000, and able to take big game ethically at those distances is not only significantly harder but also much more expensive.
And even with an expensive custom magnum rifle and precision ammunition capable of performance on game at long range, the shooter's ability with the fundamentals and experience managing a rifle with that kind of recoil will be key to his success.
Get a .308. Get good with it. Punch paper at 100, then 200, then 300. Hunt deer with it to 400 or so. Hunt prairie dogs with it to 1000.
I think you will find that there's a big difference between shooting at 100 and shooting at 300; that there's a bigger difference between 300 and 600; that in the wind 700 is another world; that, wind or not, 800 is a different planet; that the difference between 800 and 900 will feel greater than the distance between 300 and 600; and that the solar system ends at 900. When you can shoot your .308 well at 900 go to 1000, and spend some time there.
I'm not saying that what you want to do can't be done: you could always buy a used .375 Chey Tac single shot and have at it. With the money you save you could then get a Hayabusa, jump on it and twist the throttle. But if you do that you won't like either one, you will get frustrated, you'll quit, and you'll think it was the fault of the equipment.
Deciding what to buy is easy because it's not a character issue: If you want to own a cool conversation piece get one of them thousand-yard sniper rifles. I have seen many of those. They're badass. They can take game to a thousand yards. I see from another thread that even the Russians are building them now, using top secret R&D according the report. But you can't cheat the laws of nature: how well you learn to use your rifle will determine your level of satisfaction with it.