I have more than 20 paper wallets with very little bitcoin in them. How can I combine all of them together? I have a bunch of paper wallets with different small amounts of Bitcoin in them. How can I combine them all into one address without having to pay a fee for sending each paper wallet to my own account? How to do a bulk send and pay a one time fee that would be cheap?
You should import all the private keys and not sweep them.
Wallets like blockchain.info has this function where it will import the private key. In that case the private key will become part of the new wallet.

Import all the private keys into a new wallet. Thats it ! During spending the wallet will combine inputs from your private keys to spend required amount.