Look for something in the 10x50 range. Preferably FULLY multicoated, Bak4 lenses.
Unfortunately there are so many brands to choose from and the price varies depending on the brand.
I did check out a pair from Andrews Communications (Sydney based) 10x50, MB style binoculars at $349. That sounds pricey, but looking thru them, great eye relief, no colour fringing around the edges, robust feel....couldn't fault them. Not sure if they were nitrogen purged or not.
Likewise can't comment for star gazing either.
http://www.andrewscom.com.au/site-section-11.htm
I'm a great believer in that you get what you pay for.
BTW: binos in the 15x70 and up do get tiresome after a few mins holding them. You definitely need some banana chair/recliner for comfy viewing or some type of tripod/parallelogram mount.
Cheers Norm
