Alderblick binoculars have received very favorable comments from Terence Dickinson and other equipment reviewers. Besides very good optics, these binoculars have something you haven't seen for a while, a lovely hard case, very sturdy and protective, with a non-slip strap. Price, like new except for minor scuff on base of hard case, $170 shipped in CONUS. Price new would be $250 plus shipping from Canada.
If you've never used anything but 7x50s, your first views of celestial objects through 10x50s will surprise you. Why?
You are seeking luminous objects against a dark sky, which is different from night landscape viewing. As a telescope detects fainter objects at higher magnification because the sky background is darker, 10x50s show more objects and show them better than lower power binoculars. Further reading: Binocular Astronomy, The Backyard Astronomer's Guide, and especially Alan Alder's excellent article on choosing binoculars in S & T's September 2002 issue. And, of course, the most convincing argument is seeing for yourself.