Let me add a few thoughts here since you're new to long range shooting.
I will "assume" that you will be shooting some sort of scoped rifle and that your goal is not to be able to see a bullet hole on a black target 1000 yards away. I will tell you how I use my spotting scope for long range shooting.
I am an F-class competitor and I shoot mostly 1000 yard competitions. I also wind coach some teams on occasion. I do not have an unlimited budget for such toys, so I try to spend wisely.
I use my spotting scope quite a bit. It is a Kowa TSN with a 27LER eyepiece. Nothing fancy, but it's very dependable, the glass, while not ED glass or (gasp) fluorite crystal glass, is good enough for my needs. Someone mentioned birders earlier and while I agree that these people are much more into spotting scopes than shooters, their needs are very different from ours.
Birders want the very best glass they can find and that's into ED, Super-ED and even fluorite crystal lenses. They require the best color rendition possible because they are looking at the plumage (of the Norwegian Blue,) and other birds. That's their pursuit, their quest and their goal. Also they do not look at birds at 1000 yards, they will be observing these flying dinosaurs at much closer range, and they usually look up in trees and forests, not flat across a wide open landscape where the mirage roams.
When I am shooting, I use my spotting scope to look at the conditions, the mirage and when on regular targets, the scores on the adjacent targets. The 27X power of my Kowa is perfect for that, gives me a wide view and I can easily see the scores on targets. When I score for a shooter on regular targets, my Kowa at 27X is perfect for that, as I easily see the scores on the target. When I wind coach a team, I can look through my Kowa for a very long time if I have to because the glass is good enough to not cause me any headaches and the 80mm objective makes for a nice bright image.
Also, I find that ED glass has a tendency to take the mirage somewhat, a quality that I do not want in my spotting scope while observing conditions, but it's definitely something I want in my riflescope to help me aim properly.
So, I spend my money on a great riflescope with ED glass (March) and spend less money on a fine spotting scope without ED glass (Kowa).