You might need to be a bit more specific about reasonable cost and really good, it may mean different things to different people
I've settled on Opticron Discovery 8 x 32, about £150 and around 450g, they're a compromise that suits me, having previously had some excellent but huge things and some lightweight £50 10x25 that were little more than toys. I also have a 8 x 30 monocular, also Opticron, it's not as good but if I could only have the one it'd be this. I have to think about packing and/or carrying the binoculars, but on most rides the mono is with me.
Opticron do some field events, you get to have a play on all levels of kit in real world situations, if there's one near you I'd recommend it, the one I went to was very informative and no hard sell.