My latest 4K+HDR UHD blurays haul from Amazon. Picked these 5 after thorough reading of their video and audio reviews on Blu-ray.com. Main objective is actually to test my new soundbar's function of playing Dolby Atmos sound. Can't wait to watch them all, especially the sequel of the award-winning documentary Planet Earth.

Yes, as mentioned by the other bros, bluray.com would be a good site to keep track of the prices. But I also check Amazon.co.uk quite regularly as they sometimes do have some special deals for UHDs. For example, just this month I ordered 4 more UHDs from them as they were having the '2 for 30 pounds' promo. With this promo price, it is cheaper than Amazon US.

I'm using UBD-KS8500 too, so far I'm loving it. I think most of us are having it as there are not many UHD players yet out there. Later this year all the 2017 models will be out though

how bout another one ? 

Leave all to 0 to have the purest possible image from the disc

Is your TV detecting HDR from the UBD-K8500 when playing a disc? Ensure the HDMI port is configured to allow Deep Color or Wide Color (something along those lines), as it is usually disabled by default.

If you are running the UBD-K8500 via a receiver, ensure your receiver has 4K passthrough enabled (it may or may not be disabled by default) and that it is configured to allow 10-bit color (some older receivers may default to 8-bit color for 4K passthrough, check your manual to be certain).