It is because of your wallet I assume. If you are not getting the option of custom fees, then better change your wallet else they gonna rob you off your BTC. No matter what the size of transaction is, you must have option for choosing your own fees. That way transaction will take time to execute, but sometimes you don't need fast transactions. Else try to read about batch payment. Many above have given the link to know the best fees at the moment. Don't let your wallet exploit you.