[Spaceships] Benchmarks for spacecraft cost

[Agemegos]

In GURPS Spaceships spaceship components have the following prices per ton.

Armour, ice                $ negligible
Armour, stone              $ negligible
Armour, steel              $     4,000
Armour, light alloy        $    10,000
Armour, metallic laminate  $    20,000
Armour, advanced " "       $    40,000
Armour, nanocomposite      $   100,000
Armour, organic            $     6,000
Armour, diamondoid         $   200,000
Armour, exotic laminate    $   400,000
Controls                   $    40,000
Defensive ECM              $   200,000
Comm/sensors, enhanced     $    40,000
    ", tactical or science $   200,000
    ", multipurpose        $   400,000
External clamp             $     2,000
Factory                    $ 1,000,000
Habitat                    $    20,000
Hangar bay                 $     2,000
Jet engine                 $   200,000
Mining/refinery            $    20,000
Open space                 $     1,000
Passenger seating          $     6,000
Power plant, chemical      $    10,000
  "     " , fission        $    60,000
  "     " , fusion         $   200,000
  "     " , antimatter     $   400,000
  "     " , super fusion   $   600,000
  "     " , conversion     $ 1,200,000
Ramscoop                   $ 2,000,000
Reaction engine, chemical  $    40,000
    "    " , HEDM          $    60,000
    "    " , electric      $    30,000
    "    " , fission       $   100,000
    "    " , nuclear pulse $   200,000
    "    " , fusion        $   200,000
    "    " , AM thermal    $   100,000
    "    " , AM plasma     $   100,000
    "    " , AM plas torch $   200,000
    "    " , super " " "   $   400,000
    "    " , AM pion       $   200,000
    "    " , AM pion torch $   400,000
    "    " , TC torch      $   400,000  
    "    " , Super TC torch$ 1,000,000
Robot arm                  $   200,000
Soft-landing system        $    10,000
Solar panels               $   100,000
Space sails                $   200,000
Weapons                    $ 1,200,000
   "   , spinal mount      $ 1,000,000
 - ammunition, cannon      $   100,000
 - ammunition, missiles    $ 1,000,000

Fuel, water                $        20
  " , coolant              $       250
  " , ionisable (argon)    $       180
  " , rock dust            $         2
  " , rocket fuel          $       800
  " , hydrogen             $     2,000
  " , jet fuel             $     4,000
  " , HEDM                 $     6,000
  " , AM & hydrogen/water  $    20,000
  " , nuclear pellets      $    50,000
  " , uranium-salt water   $   100,000
  " , AM-boosted H2/H2O    $12,000,000
  " , nuclear bombs        $   250,000
  " , 50% AM       $10,000,000,000,000

Leaving aside GURPS's pervading problem of things not getting cheaper with TL improvement, do those figures seem okay? Is jet fuel really $16 per gallon? Is argon really only 9% the price of hydrogen? Should an external clamp cost only half as much per ton as dumb steel armour?

What benchmarks can we establish for what things ought to cost, eg. how do comm/sensor arrays compare to real life avionics prices? What does a Pratt&Whitney aero jet engine cost per ton? Are airbags really $10,000 per ton?