that's cool Nine. one of my primary hobbies is astronomy and my first tool of choice are binoculars. of course, the use is different, but of importance is light gathering power. when you have good coatings on your binocular lenses and prisms, they can often be brighter then other binoculars with larger aperture but lousy coatings.
while this is the 'best' case scenario, one wants to watch for specs such as fully multi-coated (best to find out if all surfaces are or if it's only some of the lenses) and that they're nitrogen purged and sealed. when you buy roof prism binoculars, you also want to ensure that they are phase 3 coated.
I know London Drugs has a pair of Bushnell 10x42's coming on sale for $199 with a free bag of sorts. I tried a pair of 8x30 Leupold Yosemite's and was surprised at how bad the reflection was in them...tho considering their price point, I shouldn't have been overly much.
that said, in the case of bino's, you can get a much higher quality porro prism model at the same price as the roof prism. the trade off is weight...porro's are heavier.
no doubt rifle scopes work on the same principles, but the fact you're constantly adjusting their collimation to sight yourself in, will change how I have to perceive them.
