Yeah you've kind of got a quality/construction/plastic vs. weight issue going on. So the ones I've got that would come CLOSE to meeting your criteria are:
Swarovski CL B 8X30- 473gm
Nikon Monarch HG 8X30- 451gm
Nikon Monarch 7 8X30- 437gm
Those are actual weights of binocular only. Any of...