The sum you pay for the service depends on subscription fee of the chosen strategy, your Wundertrading plan and the a minimum amount on an exchange account required to subscribe to the strategy.
You can copy trade on Free plan and choose a free of charge strategy.
Each strategy indicates a minimum amount on your exchange account required to subscribe. You’ll find this information on the strategy overview page. Therefore, this sum can be the only requirement in terms of funds necessary to start copy trading.