Answer these for yourself:
- What are you shooting (rifle, cartridge, animals, size of targets, etc)?
- How far are you shooting (max & average)?
- In what conditions?
- Weight goal?
- Any particular features that you are looking for?
- Price goal?
- How “serious” are you in getting into shooting?
Of course, scopes need to work mechanically, but in 2021 you don't have to chose between good mechanics or good “glass”. If you are shooting a lot and/or in varying conditions, “glass” will matter.
In terms of magnification range, 1x - 1.5x per 100 yards is a typical rule of thumb for practical/field shooting. I’m typically on 12x - 15x when shooting 1 - 1.5moa sized targets at 1,000 yards. High magnification ranges coupled with short scopes leads to finicky parallax, tight eyebox, distortion (which impacts reticle), dimming on high mag, etc etc. Look for about 5x magnification ranges (3-15, 4-20, etc).
If you are regularly shooting beyond about 300(ish) yards, go FFP. You’ll want your reticle to be correct on all magnifications.
Lightweight is typically the enemy of “durable” and “long range” in general. Figure 26 - 30 oz for most decent optics. A few are lighter, some are heavier. Rifles & optics are a poor place to save weight IMO.
Shooting is expensive. If you actually shoot a bunch, the price of a top tier $3k+ optic is pennies relative to ammo, time, gas, blah blah blah. Don’t set some arbitrary budget for your optic. Find the optic that is right, then save/budget to afford it. Having spent tens of thousands of dollars trying out scopes from Nikon, Bushnell, Leupold, Vortex, Nightforce, Kahles, Tangent Theta, and Zero Compromise, IME, you typically get what you pay for.
In terms of specific optics, there’s a lot of Nightforce and SWFA fanboys on this specific forum. For me, the SHV line is a pretty good $500 optic. Just so happens some folks overpay quite a bit for them. The NX8 line has way too many compromises IMO - hard pass. ATACR line is the only legitimate choice from NF, but again they’re generally over priced. I had the flagship SWFA 5-20 HD for a year. It’s an outdated scope, but good in the $800 range.
If you are on a budget, the Bushnell LRHS 2.0 is a decent sub $1,000 choice. Unilluminated Leupold Mk5 is good in the $1400 range. A used/demo ATACR is good in the $1800 range. If you go with Vortex, I’d only look at the Razor line or AMG. AMG is recently discontinued, but you can still find them used for $1800 or less. Used/demo Kahles in the $2500 range. And Tangent or ZCO in the $3500+ range. Obviously there’s way more options, but that’s very roughly how I currently break down the pricing tiers.
Expensive stuff won’t make up for lack of skill. BUT there is a strange mentality in shooting sports that tells new shooters they need to start with budget junk and somehow “earn” good gear. If you were starting to run, nobody would tell you to run 5k’s in flip flops before you “earn” good running shoes. Buy good shoes that fit up front. It’s not rocket science, buy a good optic up front.
Finally, be careful about what you read online. Lots of silliness, even/especially from forum self proclaimed ‘experts’ and reviewers. The only way to truly get experience and know what works for you is to spend the money and go use some optics. Look at the classifieds to know what sells, what sits, and what prices you can expect to get when you sell an optic.