Ok, please bear with me.
This is one of the main reasons I haven't used bitcoin (crypto currencies). It's practically impossible to get a straight answer on what it might cost to cash out.
First of all, if you want to make trades with cheap fee then you should avoid coinbase because it is having high fee structure and especially for fiat to Crypto and vice versa conversion. Better way to avoid fee is to trade via peer to peer platform which is suitable for few hundreds of dollars to purchase.
Mistakes makes the person complete.