[ayenbe]

In my BOGO experience, the items ring up x.xx and 0.00 if there is only ONE price of the item(s) in question. If there are multiple prices, they generally ring up some other mysterious way (x.xx and y.yy).

A quick example is when makeup is BOGO. There are many prices (eyeshadow singles are cheaper than eyeshadow multipacks), so they will usually both ring up full price, then the lesser taken off at the end. If the BOGO is shampoo with different types but all the same price, it will probably ring up x.xx and 0.00.

But even this logic can ultimately differ from the programmed register "logic"...