Ysterhout Dot Net
You get what you pay for. That FFP tactical illuminated high magnification scope on eBay that is supplied from China is a steal at $ 100, compared to the local retail of $ 1000 for a known brand name, but you will be getting a $ 100 scope, not a $ 1000 scope at a $ 100 price.
The price of a scope reflects the quality of components used. Good, clear glass is not cheap. A turret that tracks correctly is not assembled from paper clips.
A cheap scope will not hold zero, it will not track reliably and repeatedly, it will be damaged from repeated subjection to recoil, the optics will be poor due to focussing pnd clarity issues, and the user experience will be lacking.
If you are determined to buy a very cheap scope, then you are on track to getting a lot of first hand experience on why that is not a good idea.
All scopes cannot be used for all purposes. There are a few general purposes that most people need a scope for :
and of course there are combinations of the above, and most scopes are multi-purpose.
Purpose determines
Going into a bit of detail on the scope purpose helps narrow the field on which options are desirable, which are undesirable, and which make no difference either way.
The range you expect to hunt at. This determines reticle, turret type and magnification.
What you plan to hunt. Varmints at long range need a very different optic to big game at close range, especially when the kind of big game can kill you.
Scope weight and size is also a consideration for hunters that hunt over long distance on foot and have to carry their own rifles.
This is not so complicated as it seems, it's a lot simpler selecting a scope for this purpose than the others, because every shooting sport will have a list of what the most popular scopes are for the top shooters in that sport. For example, search online for the top scopes used in PRS. Pick a scope on that list in your budget, and you're good to go.
Choosing a scope becomes an exercise in futility when you start looking at making a certain scope fit your purpose, when it was not designed for that purpose. So avoid doing that. For example, you need a scope for PRS competition, and can't afford any of the types in regular use in the sport : avoid buying a cheap alternative that you think should be fine. No man ever made a silk purse from a sow's ear.