Will the transaction fee will high if I send small amount under $50
Actually, regarding fees, you can set them yourself. No matter how big or small the amount of btc that will be sent. However, if it's a small transaction like $50USD, I think you can still use a fee of around 19sats/vB even when the fee increase is currently occurring due to congestion on the Bitcoin network which has not yet subsided. Because with this number of transactions and with this fee, at least you can use the free accelerator service from ViaBTC.
1 I use it often and it works pretty quickly. But there are limits to the accelerator service per hour. that is, only 100 transactions will be accelerated. And currently, in just 1 minute, 100 transactions are always used on viaBTC. which indicates many are using it now.
But if you want your transaction to arrive quickly then of course using the recommended fee (the highest currently) is the best. But it will definitely be much larger than the total you sent.
----------
Reference:
1. https://www.viabtc.com/tools/txaccelerator