I am constantly struggling to find relevant costs of warships and auxiliaries when proposing defense alternatives for navies. Here is a Page specifically for this purpose, for my own reference, and anyone who needs it. Your help in finding relevant sources is much appreciated. Wikipedia is not a good source but it is a good starting point as they often post source links for their information, though not always.
This is an ongoing project. Prices are in US dollars.

Astute SSN (UK)-$2,410 million
Barracuda SSN (France)-$1.35 billion
Dolphin SSK (German/Israeli)-$635 million
Gotland SSK (Sweden)-$365 million
Improved Kilo SSK (Russia)-$350 million
Le Terrible SSBN (France)-$3.8 billion
Ohio SSBN Replacement-$7 billion (est.)
Scorpene SSK (Spain)-$825 million
Type 209 SSK (German/Portugal)-$550 million
Type 212 SSK (Germany)-$525 million
Type 214 SSK (Germany)-$500 million
Virginia SSN-$2.4 billion
Cavour CVH (Italy)-$2 billion
Charles de Gaulle (France)-$3.7 billion
CVN-78 Gerald R Ford-$13.5 billion
Queen Elizabeth (UK)-$3.7 billion
George HW Bush-$6.26 billion
Hyuga DDH (Japan)-$1.06 billion
Vikrant (India)-$762 million
DDG 51 Arleigh Burke-$1.8 billion
Daring Type 45 (UK)-$976 million
DDG 1000 Zumwalt-$6 billion
Absalon (Denmark)-$269 million
Bertholf National Security Cutter-$641 million
F100 Bazan (Spain)-$600 million
F105 Cristobal Colon (Spain)-$954 million
De Zeven Provincien (Netherlands)-$532 million
FREMM (Franco/Italian)-$745 million
LCS Freedom-$637 million
Holland (Netherlands)-$169 million
LCS Independence-$704 million
Iver Huitfeldt (Denmark)-$332 millon
Nansen (Norway)-$557 million
Sachsen Type 124 (Germany)-$1.06 billion
Valour MEKO A200 (South Africa)-$327 million
F-22P Zulfiquar (China/Pakistan)-$200 million
Baynunah (UAE)-$137 million
Braunschweig K-130 (Germany)-$309 million
Clyde (Britain)-$47,000,000
Falaj 2 (UAE)-$136 million
Khareef (Oman)-$262 million
Kedah (Malaysia)-$300 million
Knud Rasmussen (Denmark)-$50 million
BAM Maritime Action Ship (Spain)-$116 million
MILGEM corvettes (Turkey)-$250 million
Otago (New Zealand)-$62.6 million
Port of Spain (Trinidad and Tobago)-$76 million
River (Britain)-$31,400,000
Sarah Baartman/ Damen 8313 OPV (South Africa)-$20 million
Sentinel-$47 million
Sigma (Indonesian/Moroccan)-$222 million
Visby (Sweden)-$184 million
Ambassador MK III (Egypt/USA)-$325 million
Cyclone patrol craft-$31 million
Hamina (Finland)-$101 million
Rotoiti (New Zealand)-$25 million
Skjold (Norway)-$133.5 million
M80 Stiletto-$6 million
America LHA-$3.05 billion
Bay LSD (Britain)-$228 million
Canberra LHD (Australia)-$1.3 billion
General Frank S. Besson LSV-$32 million
KRI Dr. Soeharso LPD (Indonesia)-$50 million
Endurance LST (Singapore)-$142 million
Johan de Witt LPD (Netherlands)-$370 million
Juan Carlos (Spain)-$490 million
Kunlan Shan LPD (China)-$300 million
Makin Island LHD-$2.2 billion
San Antonio LHD-$1.76 billion
Mistral (France)-$529.8 million
Type 702 Berlin AOR (Germany)-$445 million
MRV Canterbury (New Zealand)-$124 million
Joint High Speed Vessel (JHSV)-$160 million
Lewis and Clark (T-AKE)-$538 million
USNS Howard O. Lorenzen (T-AGM-25)-$199 million
Patino AOR (Spain)-$288 million
Sea Fighter FSF 1-$200 million
Wave Knight Auxiliary Oiler(Britain)–$172 million
Naval Aircraft
The following numbers are based on DoD sources based via Defense-Aerospace.com. Unit Costs based on Total Costs as of 31/12/09:
  • E2 D Advanced Hawkeye-$252.05 million
  • EA 18 G Growler-$101.31 million
  • F/A 18 E/F Super Hornet-$93.38 million
  • F-35 Lightning II-$133.6 million
  • Rafale (France)-$125 million
  • MH 60 R SeaHawk-$47.47 million
  • MH 60 S SeaHawk-$29.48 million
  • NH90 (European)-$48 million
  • P 8I Poseidon-$279.84 million
  • V 22 Osprey-$115.5 million
  • CH 53K Super Stallion-$127.63 million
  • Sea Avenger UAV-$20 million
Of Interest:
  • C 130J Hercules-$90.34 million
  • C 17A Globemaster III-$311.97 million
  • CH 47F Chinook-$26.56 million
  • F 22 Raptor-$354.86 million
  • RQ 4 Global Hawk-$178.03 million