Got a Yukon NV MT2 WP (waterproof) monocular for Xmas.
Got it through ebay via High Quality Optics (have their own ebay shop) for £145 delivered direct from the Ukraine in 10 days.
You can get a full range of accesories including scope adapter, head mount, camera/video output etc.
Check them out, it's good for up to about 100 yards dependent on conditions but they do need a bit of getting used to.
Just to add that this is not a state of the art piece of kit. It is no substitute for fieldcraft and stealth but can be a handy tool.