Medela PISA: Why so many different bags?

dfoley1111

I see a metro bag $330, on-the-go tote $295, backpack $280, and shoulder bag $250. Is there any difference in the actual pump?

 

These prices are from BRU and I?ve been looking at the description and I feel like I must be missing something because there shouldn?t be so much of a price difference just because of different carrying cases. TIA!