Zavvi and Zoom in the UK have the individual Star Wars films (including Rogue One and Solo) for sale at £20 each (or 2 for £30).
Each release is a 3-disc set; containing the 4K, blu ray, and bonus disc:-
https://www.zoom.co.uk/category/marvel_studios_multi_buy_2_4k_uhds_for_30
https://www.zavvi.com/offers/disney/multibuy/4k.list
Edit: HMV are doing the same £20 each / ‘2 for £30’ offer too - https://store.hmv.com/store/hmv-offers/marvel-star-wars
bluray.com threads for the 3-disc 4K UHD releases of the individual Star Wars films in the UK: SW : ESB : ROTJ
Rogue One is now finally available in 4K in the UK too - bluray.com thread 😃