Will the transaction fee will high if I send small amount under $50
The bitcoin network and network congestion doesn't care whether your transaction amount is $10 or $100. Whenever the network is congested and the fees for transaction is $42, that is what you will pay for the transaction amount. The network congestion is one of the factors responsible for a high transaction fee. The two ways to minimize the transaction fees are to wait for the times when there will be lower network congestion or use another cryptocurrency.