The point Richelle has made about prices not ending in a whole amount is called price pointing in marketing terms. $17.00 sounds much more to a customer than $16.99.
In reality the difference is of course just one cent, however you are using price pointing to promote the number 16 in the customers mind, not the number 17 which you are actually charging in reality.
So in essence, the customer will look at the 16, ignore the 0.99 and think of the item as a 16 dollar item, not as a 17 dollar item.
It's one of the oldest and best marketing tricks I know, absolute classic and it works!