Coinbase is one of the few entry points into Crypto for US citizens, and boy do they milk it. Have you seen the fees for buying 1 BTC? And just to rub your nose in it, you can guarantee that the price quoted is at least $10 above the maximum Ask price on say Bittrex. So I just entered this at 4:40pm Tues 12th
and here's the market at the same moment
So they first gouge you on the fee and then on the actual price, so they win twice. But wait!! The fees are not fixed but are a percentage of the purchase. So here's a quote for 3 BTC and it requires no more effort or cost for Coinbase to buy 3 BTC for you versus 1 BTC, but the fee tripled
The moral here is buy Coinbase because they must be making a fortune out of every single customer