Not just complexity, but vagueness. Good luck writing a program that calculates what's "reasonable". Was the construction work a "repair" or an "upgrade"? How

Not just complexity, but vagueness. Good luck writing a program that calculates what's "reasonable". Was the construction work a "repair" or an "upgrade"? How about determining what would be a reasonable amount for someone to pay if they were in the shoes of the businessperson but dealing at arm's length?