spend some time on here reading and searching and you'll be able to answer almost all your own questions. They've all been asked numerous times before. You've already been given two good options for a scope in your price range in your other thread. They were the Vortex crossfire and the nikon buckmaster. These are both good scopes fro the price. SWFA has the crossfire on sale for $99 right now. Buy two of them. I did.
I bought one about 6 months ago. A 6-24 x40 for a 17 rem fireball. I figured it would be good enough for the low recoil rifle I only shoot to 300 or so. I bolted it on and while sighing it in I was discuraged of the 1 1/2" group sizes @100 yds. Plus when I cranked it up it became terribly cloudy. I took it right back off and went and bought a Vortex Viper. Groups were right back at 1/2 to 3/4" easily. My advice is save your ammo, time and trouble and keep lookin.
+1, if you need something inexpensive for an airgun or a rimfire it'll probably get the job done. It depends on you're price range. The barska I used to have I bought for 39.00. Not really reliable and and the glass isn't the best out there. I sold it, and spent another 100.00 and got a mueller and have been very pleased with it for rimfire use.