Tennis ball prices (can of 3 Penn hard court balls):
	Sports Authority	7.49/4	(8/04/98)
	Sportmart		2.09	(3/19/98)
	Walmart			2.09	(11/29/97)
	Kmart			2.29	(11/29/97)
	M C Sports		2.27	(11/29/97)
	Venture			1.99	(2/26/95)
	Ace			3.67	(2/5/95)
	Target			2.29	(10/26/93)
	Service Merchandise	2.29	(9/25/93)