Coinbase has a good reputation for security and ease, but a bad reputation for fees.
The fees for buying and selling crytos are indeed high.
Some say there are hidden charges, there aren't, you just need to understand how it works and how to avoid it.
Let's take an example, I want to sell BTC for Euros:
As can be seen, the purchase price (on the right) is lower than the market price (on the left), this is due to a margin of safety that Coinbase takes because the market fluctuates very quickly. This 0.685% margin here can go up to 2%. (Spread fee)
Transaction fees (called Coinbase fees) are added on the basis of 1.49% with flat fees for amounts lower than 200$:
If transaction ≤ 10$ fees=0.99$
10$< transaction ≤ 25$ fees=1.49$
25$< transaction ≤ 50$ fees=1.99$
50$< transaction ≤ 200$ fees=2.99$
Now I will explain to you how to reduce the fees:
You need to use the Coinbase exchange called Coinbase Pro https://pro.coinbase.com/
It automatically links to your Coinbase account if it is opened in another tab.
Transfers from Coinbase to Coinbase Pro and reverse are free and instantaneous.
Where it gets interesting is that the exchange fees on Coinbase Pro are only 0.50% (maker or taker), compared to Coinbase's 1.49%.
The market is very active and fast, but the interface is pleasant and practical.
Now you know how to lower your Coinbase transaction fees.
The conversion between 2 cryto currencies also costs 2% margin fees on Coinbase, so I advise you to use Coinbase Pro for conversions too.
The fees for withdrawing to an external wallet with Coinbase Pro seem quite low too, but need to be tested further, I am just giving an example for a Dash transfer: