message: Labourers cost the same as workers
diff: <bBuild>1</bBuild>
  </Build>
  </Builds>
  - <iCost>120</iCost>
  + <iCost>60</iCost>
  <iAdvancedStartCost>100</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  <iMoves>2</iMoves>
  <bBuild>1</bBuild>
  </Build>
  </Builds>
  - <iCost>120</iCost>
  + <iCost>60</iCost>
  <iAdvancedStartCost>100</iAdvancedStartCost>
  <iMinAreaSize>-1</iMinAreaSize>
  <iMoves>2</iMoves>
  