Quote from: howtobuybtc on May 25, 2017, 10:58:02 AM

using cash - here again fees may be far higher than when purchasing with a bank transfer. The advantage of buying bitcoin with cash is that you can stay anonymous and no ID verification is needed. The main disadvantage is that you may need to actually leave your room and meet someone or go deposit money to finalize the transaction

it is not exactly called "fee" when you use cash, because there is no fee you meet face to face and hand over the cash and receive bitcoin payment in your wallet.
the reason why it costs more is because of the "spread".
when using cash you are paying for privacy and the sellers know this and will ask for a higher price and also buy at a much lower price because the demand will be there and also they have to make profit too.