message: Reduced cost of some National Wonders
diff: <PrereqTech>TECH_ECONOMICS</PrereqTech>
  <GreatPeopleUnitClass>UNITCLASS_GREAT_MERCHANT</GreatPeopleUnitClass>
  <iGreatPeopleRateChange>1</iGreatPeopleRateChange>
  - <iCost>450</iCost>
  + <iCost>400</iCost>
  <iHurryCostModifier>50</iHurryCostModifier>
  <iAdvancedStartCost>-1</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  <PrereqTech>TECH_EXPLORATION</PrereqTech>
  <GreatPeopleUnitClass>UNITCLASS_GREAT_MERCHANT</GreatPeopleUnitClass>
  <iGreatPeopleRateChange>1</iGreatPeopleRateChange>
  - <iCost>450</iCost>
  + <iCost>400</iCost>
  <iHurryCostModifier>50</iHurryCostModifier>
  <iAdvancedStartCost>-1</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  <PrereqTech>TECH_MACROECONOMICS</PrereqTech>
  <GreatPeopleUnitClass>UNITCLASS_GREAT_MERCHANT</GreatPeopleUnitClass>
  <iGreatPeopleRateChange>1</iGreatPeopleRateChange>
  - <iCost>600</iCost>
  + <iCost>500</iCost>
  <iHurryCostModifier>50</iHurryCostModifier>
  <iAdvancedStartCost>-1</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  <PrereqTech>TECH_SCIENTIFIC_METHOD</PrereqTech>
  <GreatPeopleUnitClass>UNITCLASS_GREAT_SCIENTIST</GreatPeopleUnitClass>
  <iGreatPeopleRateChange>1</iGreatPeopleRateChange>
  - <iCost>600</iCost>
  + <iCost>400</iCost>
  <iHurryCostModifier>50</iHurryCostModifier>
  <iAdvancedStartCost>-1</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  <PrereqTech>TECH_HERITAGE</PrereqTech>
  <GreatPeopleUnitClass>UNITCLASS_GREAT_ARTIST</GreatPeopleUnitClass>
  <iGreatPeopleRateChange>1</iGreatPeopleRateChange>
  - <iCost>500</iCost>
  + <iCost>400</iCost>
  <iHurryCostModifier>50</iHurryCostModifier>
  <iAdvancedStartCost>-1</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  <FreePromotion>PROMOTION_MEDIC1</FreePromotion>
  <GreatPeopleUnitClass>UNITCLASS_GREAT_SCIENTIST</GreatPeopleUnitClass>
  <iGreatPeopleRateChange>1</iGreatPeopleRateChange>
  - <iCost>600</iCost>
  + <iCost>500</iCost>
  <iHurryCostModifier>50</iHurryCostModifier>
  <iAdvancedStartCost>-1</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  