According to the GRO indices he died Q4 2014 Herefordshire. According to a note I found in social media, he died 11 December 2014.
He was son of John Powell GREEN-PRICE (1878 - 1927), 5th son of Sir Richard Dansey GREEN-PRICE, 2nd Bt (1838 - 1909), and Julia Helen Oucherlony NORMAN (died 1956). He was adopted by his uncle, Sir Robert GREEN-PRICE, 3rd Bt.
He was lately heir presumptive to his nephew Sir Robert, 5th Bt (born 1940). His son, Simon Richard GREEN-PRICE (born 1964) is now heir presumptive. Initially I thought he was the youngest heir to the title (listed by Kershaw as A 1964), with only one further heir John Chase G-P. (b 1947), however, social media gives the possibility of Simon having a son: M P G-P. (b Q4 2005, m/m/n FELLOWS). Simon is found living in Electoral Roll records living with a Tracy FELLOWS 2006-2018 (with a couple of year-long gaps) in post code HR6. I am unable to locate a marriage for GREEN-PRICE/FELLOWS - in
this article Tracy is described as his partner, so their son is probably not in remainder.