Im not 100% sure but i think the amount you want to send creates tx with a high fee because of the congested network causing the fee to be higher than the amount to send or a fee so high that the amount to send is lower than the fee. I could be wrong though.
no i need to send $300 and i see fees $17
If you're not even spending an amount greater than what you have but you're still seeing the error sign then please refer on my previous post as this is most likely a problem in blockchain.info's end so for obvious reasons, they're the only ones who can fix it.
https://bitcointalk.org/index.php?topic=2633365.msg27019690#msg27019690