Is that $3000 per Level of house ?
36sq house or 360sqm house would have apox 120 lineal meter of External wall
Te increase in wall height would add 2 brick courses around the outside so about 1000 bricks. Depending on brick type:rule of thumb is $1 brick and same to lay it so $1000 labour $1000 for brick = $2000 plus extra in Plaster internally 3K would seem reasonable per Level of house .
Its for just the ground floor...so would you say they are charging twice as much?
I think it is about 323sq - may be more like 35sq