I wouldn't buy anything in the 12-13X range until I had and had used the basic 7-8X42 for a while. The big 12's, and presumably the 13X binoculars, really can show you things that you can't see with the lesser binoculars. But... they are highly specialized. You either drag a tripod around with you or you have to put up with some eye strain from the image shake. They can't be used from standing to any degree. In order to really show you much, the subject would have to be literally 3 plus miles out.
I wouldn't do a 10X50 as any kind of primary either. You really do need an 8X for that in my book. I suggest you try out some 10X50's from Doug. And some of the 7-8X42's. Unfortunately, the last heard, he doesn't sell the 8X42 Meopta. Midway does. I don't know if they will let you buy one and return it just becasue you weren't completely satisfied. I think they will, but I'm not sure. You might check with them.
BTW, you might keep your eye peeled for a Leica BN on sale in 7-8X42. Somebody might have them somewhere at a steal. E