Unless they are rated as "fog proof" you will run into problems when moving from a warm environment to a cold one. For instance, if you glasses are kept under a coat or sweatshirt and brought out, they can and will fog.
Gas purged binocs, while more expensive eliminate this problem.
In optics, you definitely get what you pay for. Go into a well stocked store and look at Svwarofski, Zeiss, Leica, Steiner binocs. Then look at
Bushnell, Simmons, Baush & Lomb, Tasco etc. You won't believe the difference.
I saved up and bought a pair of Steiner peregrins, 10X40. I think I paid around $700 or a little less on eBay. The brightness, clarity, definition and ease of use is incredible.
You get what you pay for.
Dana