As has been said get yourself a top quality fixed mag Euro - 8X56 is the most common for foxing and low light work and generally if everyone is using something then they are doing it for a reason. I use an 8X56 for all my stalking which is mostly in forestry but with the occasional bash for red deer on the hill. The sika in forestry are usually shot in dense cover at very last light and I've shot them at ranges from 20 yards to 250 yards.
I think S&B offer the best second hand value - get a Hungarian one as they are less expensive but offer the same quality. Zeiss offer slightly better glass, but nothing to get worked up about, and Swaro are exactly the same as S&B in low light, as best me and a bunch of mates could determine, so don't get too worked up on brands but be aware that you will probably pay more for Swaro and Zeiss for no practical gain.
The big plus with buying top notch Euro glass is that there is always a market for them and so even if you don't like yours you will sell it for what you paid for it. I bought my 8X56 S&B for £250 and could probably sell it for more than that now. In the end there is nothing to beat having the best available quality and it costing you nothing, or even making money, while you are using it.