where can I quickly buy ETH?

There is a service Changelly, but there is a high commission. I change on localbitcoin or streamdesk when its not a big amount

Also heard about them. The service is fine, but now there are not enough options for exchange. They just started, but its quite interesting

What is the problem to buy on exchanges?

At the stock exchange youll pay commission for fiat and with banks its a long process

I dont know, I use stock exchanges, no problems. And whats the service? What are we talking about?