he is the list of Rare Pieces with the number printed so you'll know what you should worry about, the others are very common
Short Line (1) $5,000,000 ($250,000 per year for 20 years)
Boardwalk (1) $1,000,000 ($50,000 per year for 20 years)
Pennsylvania Avenue (2) $50,000
Ventnor Avenue (10) $10,000
Kentucky Avenue (50) $5,000
Tennessee Avenue (100) $1,500
Virginia Avenue (250) $1,000
Vermont Avenue (500) $500
Mediterranean Avenue (5,000) $50