Help me understand this please...
 

I just bought 5 books and they were all cheaper as paperbacks then they were as eBooks.

3 of them were older books, but two of them were Stieg Larsson's books so they were relatively new.

Why would paperbacks be less expensive than the eBooks considering there are no printing costs?

Thank the agency pricing model. The big 5 or 6 publishers colluded with certain fruit-named companies to force Amazon to sell ebooks at higher prices. Any time you see "This price was set by the publisher" in the description, you can assume the price was jacked up by one of the big publishers.

depending on where you live, it would amount to the same sum (if not more) if your purchased paperbacks+shipping costs.
amazon apparently includes around $2/$3 as "whispernet fee". it also depends on whether the equivalent paper book is a hardback or a paperback.
then there is the public enemy no 1: the publishing house (it's the one that sets the starting price and imposes all sorts of restrictions on the sellers, like amazon)
this has been discussed over and over :(
if you go over to the "kindle community" at amazon, you'll see 100+ threads on the subject as well as boycotting efforts.
i still prefer the extra tariff for the advantage of having the book in under 30 seconds.