Transaction Fee

[citycoiner]

Hi,

New to the forum, I have been holding bitcoin for about 2 years in various wallets and never had a need to "move it". Recently I wanted to transfer 0.5 BTC from Breadwallet to coinbase and got quoted almost $400 in transaction fee. When I dropped the value to 0.25BTC it went to $4. Can someone explain why the high cost of transaction fee? Doesn't this go against all the value proposition of "low cost money remittence"?