Most of us speak USD, not the currency unit you mention. But it is the same story. You are comparing apples to oranges. Although it was not always the case, today with the internet and all you probably CAN purchase equipment on your own. But put empahsis ► ON YOUR OWN. A contractor would purchase the equipment wholesale, not necessarily much less than the prices you have found, and YES he will mark it up selling it to you. IN RETURN, he will probably provide labor coverage on any warranty repairs later. If you stiff him out of his profit, and just pay him to install the equipment, then the manufacturer will provide you parts on the warranty issue, but WHY would your guy come in and do that work for free???
As far as the total labor cost to do the work, don't try to compare it to what you think a PERSON's hourly rate of pay is. You are hiring a CONTRACTOR who has expenses...office expense, truck expense, huge insurance expense, payroll taxes, etc etc. Why do you think a lawyer ( barrister??) charges $350 per hour, a doctor $500?? You are paying for the total business, not just what the lawyer himself makes on it. Around here, the going rate for auto repairs is in the $80 to $100 per hour range. The mechanic himself is NOT taking home even CLOSE to that number!