need to remove duplicates in rows that take up two columns

Ok here it is: I have data set up in the following format:

item number, sales date, price, sales date2, price2, sales date3, price3

the problem that I have is that sales date2 and price2 are the same as sales date3 and price3.

if any of the sales dates and sales prices match I need to erase one of them. (ONLY if both the date and the price match)

Thanks,
Z