Pawn + Bishop

requires:
• 

cost: 4

Pawn + Knight

requires:
• 

cost: 4

Pawn + Rook

requires:
• 

cost: 6

Rook

requires:
• 
• 

cost: 5

Knight

requires:
• 

cost: 3

Knight + Rook

requires:
• 
• 

cost: 8

Bishop

requires:
• 

cost: 3

Bishop + Knight

requires:
• 
• 

cost: 6

Bishop + Rook (Queen)

requires:
• 
• 

cost: 8

Amazon (Bishop + Knight + Rook)

requires:
• 
• 
• 

cost: 11