Are these differences so that people can make a profit and incorporate fees that are involved?
Examples from localbitcoins

12377 price/btc on localbitcoins if going through say a bank transfer
16562 price/btc on localbitcoins if going through say paypal
11200 price/btc on coinmarketcap

I know paypal transactions are known to have high fees, but why?  and why such a huge jump like that? That is thousands of dollars in difference.