I've recently interviewed with a company, at the end of the interview, they asked me what my expected salary is. I made the mistake of saying a somewhat low range (somewhat bellow average for that location). I'm currently finishing a MSc program and the position is in a different country within the EU. I consider to have relevant experience already in the field.
On the interview, we did't discuss any of the actual benefits (bonuses, working hours, vacations etc), or the details of the work itself.
How can I avoid to make a bargain of myself in further interviews (same company)? I'm also interviewing with 2 different companies in the same city, can I use this to negotiate a better salary even when I've already set a lower expectation?