Head is the opposite of Toe. Toe is the opposite of Finger. Finger can be used for Point. 
Price is related to Buy. Buy is related to Give. Give is related to Donation. 
Head <--Antonym--> Toe <--Antonym--> Finger --UsedFor--> Point 
Price <--RelatedTo--> Buy <--RelatedTo--> Give <--RelatedTo--> Donation 