Price is related to Deal. Deal is related to Trade. Trade is related to System. System can be used for Efficiency. 
Seller is related to Occupation. Occupation is derived from Occupy. Occupy is a synonym of Absorb. 
Price <--RelatedTo--> Deal <--RelatedTo--> Trade <--RelatedTo--> System --UsedFor--> Efficiency 
Seller <--RelatedTo--> Occupation --DerivedFrom--> Occupy <--Synonym--> Absorb 