Let's do some math ..  Rounding examples of 7 random hypothetical purchases:
Case	Tag   Price	Sales   Tax %	Raw Total   Incl. Sales Tax	Rounded   to Penny	Rounded   to Nickel	Rounded   to Dime
Purchase #1	$195.54	11.234%	$217.507	$217.51	$217.50	$217.50
Purchase #2	$55.39	13.428%	$62.8278	$62.83	$62.85	$62.80
Purchase #3	$221.89	10.670%	$245.5657	$245.57	$245.55	$245.60
Purchase #4	$226.61	13.360%	$256.8851	$256.89	$256.90	$256.90
Purchase #5	$213.78	7.285%	$229.3539	$229.35	$229.35	$229.40
Purchase #6	$205.51	10.593%	$227.2797	$227.28	$227.30	$227.30
Purchase #7	$209.32	8.686%	$227.5015	$227.50	$227.50	$227.50
7 purchase totals =	$1,328.04		$1,466.9207	$1,466.93	$1,466.95	$1,467.00