Question about Logitech M705 Marathon

Why buy one Logitech M705 mouse rather than another? If you look up the Logitech M705 wireless mouse in digitec, you'll find listings under product numbers 14153870 (today for 42.90), 5939901 (41.00), 225533 (70.92) and 12646651 (62.30). Which should you get? Any of them. They're all the same mouse, packaged differently. The shells may even look a bit different, but the works and electronics are identical. Why does Logitech sell the same mouse at different prices in different packages? I have no idea. (I'll try also to post this under the other three listings.)