What are you looking to use it for? Spot game you are thinking of shooting, recognize bullet splash/hits on steel, or trying to see holes in paper etc and shooting at rocks? That’ll have a lot of effect but the swaro 95mm is the gold standard if you don’t need a reticle in it.
Welcome to RS. As mentioned above, it depends what the target is and you will be limited by mirage. No spotter can eliminate mirage.
Price dictates quality.
It would be our pleasure to discuss different options with you if you'd like to give a call, 516-217-1000
If you are target shooting only and want to save move get a wireless camera system as the thermals can make even the best spotter unusable. Otherwise, Kowa TSN883/4 with the TE11 eyepiece, Zeiss, Leica or Swaro.
Like a lot of other comments above, it depends what you want the scope for. I use a Meopta Meostar S2 with the 30-60 WA eyepiece and a Meopta TGA-75 collapsible spotting scope for hunting, depending on space/weight concerns.
For straight up long range (1200+ yards) match shoots, I use a Bushnell Elite Tactical LMSS 8-40x60 Spotting Scope with Horus H-32 reticle. The glass is not as good as the Meopta S2 but it is decent but the Horus reticle is great for spotting misses for a shooting partner and then being able to tell them in 0.2 mils how much up and over they need to correct rather than something like 2 targets up and a half a target to the left. I used it a lot to teach my son precision long range shooting. It is an excellent scope for precision shooting corrections. The other great thing about that scope is that the magnification goes all the way down to 8x which is very rare in a full size spotting scope so I have even used it for hunting in hot conditions when the mirage would blur anything above 30x.
Like others have stated, more details are needed to answer your question correctly. For general purpose long range shooting, our favorite set-up is a 95mm Swarovski with a BTX eye piece. The BTX module allows you to look through the spotter with both eyes which makes it easier to follow trace and observe impacts.
Clarity of glass is more important than magnification. A Kowa 553 is better than Vortex 65 and 85... With mirage, magnification only makes it worse. And, the too end of all scopes gets mushy compared to the sweet spot.
I find I do most of my spotting in the 20 to 30 range regardless of the spotter. My buddy with a Kowa 88 spots in the 20 to 35 range.
I can spot at 1000 with 12x binos on a tripod, so it just depends on what you want to do with it. I can't see impacts on the target as clearly as a spotter, but I can call hits and misses.