Possible Clues:

• Do some price negotiating
• Is it healthy to welcome horse trade?
• Argue trivially
• Bargain brings delight, no end, to ugly old dame
• Dispute about price
• Try to knock down
• Vie for a better price
• Dicker over a price, say
• The way to bargain, for the horse in good health
• Going great guns, initially, in hearty way, to get a good price