With optics, you get what you pay for.  Russian scopes are inexpensive.  You do the math.

But to illustrate, here's some examples:

[img]home.attbi.com/~kisara/wsb/media/66713/site1041.jpg[/img]

[img]home.attbi.com/~kisara/wsb/media/66713/site1047.jpg[/img]

Notice the fuzzy haze around the outside, the ultra-busy reticule, the lousy illumination, and the overall dark, grainy picture?

[img]home.attbi.com/~kisara/wsb/media/66713/site1040.jpg[/img]

This is the same angle as the first pic, but through an ACOG.  Notice the crispness in the pic, even out to the edges, the wider field of view, and the brighter picture?

[img]home.attbi.com/~kisara/wsb/media/66713/site1046.jpg[/img]

This is the same view as the second shot from the ACOG, a little closer so you can see the detail better.  Again, quality is MUCH better.

Then, you have factors such as toughness, adjustment reliability and repeatability, water-proofing, and so on, all of which are going to be marginal on a cheaper scope, because that's where the savings come from.

-Troy