If possible choose between Leica and Zeiss.
If on a budget, see if Swift still makes their 8.5X44 Audubon roof prism glasses. They have been been an exceptional value.
I own all three, but that Swift has impressed me as being the best deal on the market, and I've used and owned most famous brands. I won't say that they are fully the equal of the others, but for about $450 at discount places, they come surprisingly close. They easily eclipsed some other famous brands made in Japan.
Frankly, I am not as impressed with some of those Japanese items as some reviewers have been.
Turn the binocular over and examine it inside for lint, fingerprints, smudges, fungus and other things that shouldn't be there. Use a strong flashlight. I think you'll find the German brands and Swarovski to have consistently the highest quality control, although individual examples of the best Jap items can also be good. (I have used only one Kahles glass, and it was fine.)
On used optics, do that test, and also look for hazing of the lenses caused by leaving the binocular in a hot car. The rubber in the seals will be vaporized and cloud the lenses. Do NOT NOT NOT leave optics in hot cars!
T-Star
P.S. Has anyone here ever noticed that my abbreviated name is Zeiss's lens and prism coating? (T-*) It was a coincidence, but it amuses me a little. But then, I'm easily amused...