Whether buying, selling or sending Bitcoin, Ethereum, Bitcoin Cash, Litecoin or any other cryptocurrency for that matter, you will be required to pay a network fee. These fees are over and above the amount that you are buying or sending, and are incurred by the network and not Oobit. Oobit does not profit from network fees.
Network fees are small fees paid to miners for verifying and facilitating the transaction. Without them, the transaction would not take place or be added to the blockchain network. Here is a more in-depth look at how Bitcoin transactions work, to get a clearer perspective.
These fees are either a small percentage of your transaction or a set fee, as is the case on the Litecoin network. They also fluctuate according to how busy the network is. I.e. if there is a large volume of transactions happening at once, the fees will increase to ensure that the demand is met.
Network fees are calculated at the time of the transaction, and will always be displayed before confirmation. Oobit does not play a role in determining the fee amount, merely that it is enough to conclude the transaction.
Here are some useful links to determine the realtime: