For several months, Amazon Prime in the US has had Season 3 available to "purchase" in UHD -- and now it's finally on sale for $9.99.
Season 3 was shot in 3.2K, but finished in 2K. This would mainly be worth getting for the wider color range offered by the UHD spec, as well as alternate color timing and avoiding some of the banding present in the Blu-ray during darker scenes.
Note that most special effects heavy films from the late 2000s until the late 2010s were also only finished in 2K... from the three Abramsverse Star Trek films to Prometheus and most MCU films. So it's fairly common for releases to use UHD this way.
Seasons 1 and 2 are not available in UHD versions. However, the second season is on sale for $4.99 in HD.
Season 3 was shot in 3.2K, but finished in 2K. This would mainly be worth getting for the wider color range offered by the UHD spec, as well as alternate color timing and avoiding some of the banding present in the Blu-ray during darker scenes.
Note that most special effects heavy films from the late 2000s until the late 2010s were also only finished in 2K... from the three Abramsverse Star Trek films to Prometheus and most MCU films. So it's fairly common for releases to use UHD this way.
Seasons 1 and 2 are not available in UHD versions. However, the second season is on sale for $4.99 in HD.