A company has an item of land carried in its books at $1,000. Two years ago a slump in land made its carrying value reduced from $1,200. (That is, its book value should be $1,200; but this slump made its book value down to $1,000 two years ago). There has been a surge in land prices in the current year, however, the land is now worth $1,800. There should be a credit entry in revaluation surplus. The amount of entry is $