It has been said previously; but you only get what you pay for when it comes to any optic, especially if your going to actually take it outside and use it. So spending 50-100 bucks my be okay to look at "chickadees" out the kitchen window, but for deer and ducks, you want 10x 42-50, waterproof, shockproof and as clear and crisp as you can afford, especially when your looking at ducks as there not very big to start with. Anything over 10x becomes to jerky in the hand to properly see ducks at a distance.
I was an avid duck hunter years ago and my wife kept buying me Tasco and Bushnell binoculars. Not really worth the box they come in, in fact I still have several of the boxes but the binoculars are long gone. They would get wet and fog up, get dirt and dust on the inside of lenses to the point you couldn't see much out of them. Two pairs I just chucked over the side of boat, as the warranties aren't worth nothing either.
So my experienced advice is, go out and buy one very good pair of binoculars. Spend at least 6-700 bucks on a pair. Personally I have a pair of Vortex Vipers 10x42's, with tax 700 bucks. Very crisp clear glass edge to edge, and a life time replacement warranty.