Kindle edition vs paperback/hard copy

I bought a used 2nd generation Kindle, and I really like it.  Especially now that I actually have time to read.  One thing bothers me about Kindle e-books (don't know if this is true for Nook or other formats but it probably is).  Why do so many Kindle books cost as much or more than the paperback?  Some titles are available for borrowing if you have Amazon Prime, and there are many books available for $2.99 or less, and some are available for free. But many titles I have searched for cost as much or more than the paperback edition.  OK, I understand that with a Kindle edition, I have a copy that does not take up space in my bookshelf or wear out, but I can't lend it to anyone. I used to share my paperbacks & book club editions with my father or my sisters.  If the Kindle edition is more than $2.99, I prefer to get it from the library and return it when I am done.  Supposedly, my library offers e-books including Kindle versions, but the wait list is very long, and it seems like I can get the paperback or hardback copy much faster.  I asked the librarian about this and he told me it was a statewide wait list, and it moves faster than I thought, so I will try requesting a Kindle book.