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	$194.42	7.575%	$209.1473	$209.15	$209.15	$209.10
Purchase #2	$91.91	4.454%	$96.0037	$96.00	$96.00	$96.00
Purchase #3	$138.38	12.403%	$155.5433	$155.54	$155.55	$155.50
Purchase #4	$152.63	3.845%	$158.4986	$158.50	$158.50	$158.50
Purchase #5	$147.57	3.339%	$152.4974	$152.50	$152.50	$152.50
Purchase #6	$94.40	3.262%	$97.4793	$97.48	$97.50	$97.50
Purchase #7	$142.50	9.339%	$155.8081	$155.81	$155.80	$155.80
7 purchase totals =	$961.81		$1,024.9777	$1,024.98	$1,025.00	$1,024.90