Table:
text: Type 21 frigate
Ships
Ships
Pennant Name_ Hull_builder Ordered Laid_down Launched Accepted_into_service Commissioned Est_building_cost Fate_
F169 Amazon Vosper Thornycroft, Woolston 26 March 1969 6 November 1969 26 April 1971 19 July 1974 11 May 1974 £16.8M To Pakistan as Babur
F170 Antelope Vosper Thornycroft 11 May 1970 23 March 1971 16 March 1972 30 June 1975 16 July 1975 £14.4M Bombed by Argentine A-4 Skyhawks on 23 May 1982 and sank following day in San Carlos Water
F172 Ambuscade Yarrow Shipbuilders, Scotstoun 11 November 1971 1 September 1971 18 January 1973 23 August 1975 5 September 1975 £16.5M To Pakistan as Tariq

text: Type 21 frigate
Ships
Ships
Pennant Name_ Hull_builder Ordered Laid_down Launched Accepted_into_service Commissioned Est_building_cost Fate_
F173 Arrow YSL 11 November 1971 28 September 1972 5 February 1974 16 May 1975 29 July 1976 £20.2M To Pakistan as Khaibar
F171 Active Vosper Thornycroft 11 May 1970 21 July 1971 23 November 1972 2 June 1977 17 June 1977 £24.1M To Pakistan as Shah Jahan
F174 Alacrity YSL 11 November 1971 5 March 1973 18 September 1974 2 April 1977 2 July 1977 £23.8M To Pakistan as Badr
F184 Ardent YSL 11 November 1971 26 February 1974 9 May 1975 10 September 1977 14 October 1977 £26.3M Bombed by Argentine A-4 Skyhawks on 21 May 1982 in San Carlos Water and sank following day in Grantham Sound
F185 Avenger YSL 11 November 1971 30 October 1974 20 November 1975 15 April 1978 15 April 1978 £27.7M To Pakistan as Tippu Sultan

Question: Which ship had the highest estimated cost of building a Type 21 frigate?