If you're looking to buy a lifetime investment, definitely spend some time choosing. Actually look through different models. As a generality I'd say buy something known to be high quality, not just "for the money." There's a lot more to a binocular than what you see when looking through it. Construction-materials-precision can't be seen but make a difference in cost and longevity.
One thing....when going from one to another the visual differences can be slight and hard to see. But get used to a really quality pair of binoculars and then switch back to lesser / cheaper ones, and the difference will be huge.
I'd read good things and got a good price on the 10X42 Minox. And it was clear and sharp and bright, but when scanning an area there was something not quite right. Objects seemed to change shape.....it was only barely perceptable, hard to really see but enough to tell that something was going on. It was just annoying enough to not want for a lifetime of use. I traded them up for a 10X50 Leica and couldn't be more satisfied.....they're about as perfect as you could expect a binocular to be. But kind of heavy.....great for stationary use but I wouldn't want to carry them all day.
For smaller and lighter, I had an 8X30 SLC Swarovski. Terrific binoculars that feel good in the hands, and a perfect size for walkaround. Beautiful optically and a really quality product, but eye relief wasn't quite comfortable because the eyepeices didn't hit quite right. So they were sold. Leica fits me well and I'll probably get another pair.
If at all possible, find a place that carries a bunch of different brands and compare them. Inside even a large building like Sportsmans Warehouse doesn't compare with being in the field but you can still see differences. Look for field of view, and look for brightness in dark corners of the room. Also look for no wavering of the picture when panning and look for straight lines bending at the FOV edge.....you'd be surprised at how many "top end" binoculars will have some of this. And especially, it's really surprising how different they all feel....how the eyepieces hit your nose and eyebrows and how it affects eye relief. Some binoculars just don't fit. Also where the focus knob is and how natural is feels during adjustment. There can be a big difference one to another and you just don't know without actually trying them.
Every eye looks through the same piece of glass and sees something different. The real shocker is looking through binoculars and closing one eye, then the other.....it's amazing how different the colors and view can be from one eye to the other. Then imagine how this can carry over into what people see through a riflescope and realize why there are so many opinions about what's better than something else.
Personally, I wouldn't put birdwatchers as the authority on optics. Varmint shooters spend hours and hours glassing. A day prairie dogging or rockchucking will add up to a tremendous amount of time spent looking through binoculars, and the demands are at least as rigorous as looking at birds.
