I've successfully navigated the job market and landed myself a graduate position for a junior developer job. I'm about to start working at an organisation which offers a base salary of ~$48K(AUD). While this is more than I have ever earned in my life and is more than enough to support myself and partner, I get the feeling that it may be lower than what I can get elsewhere. Advertised government positions for very similarl positions offer $10k more than this straight off. I only found this out after the interview stage (naive I know :) ).
I also got the impression that the salary was fixed and not particularly negotiable. As I have no bargaining power (no-experience and slow job market) I feel that asking for more, even with justifiable reasons and evidence could very well cause some problems and label me as a malcontent.
My question is generally then: What would be good tactics to raise these issues, while avoiding problems if possible?
As a side question, I'm wondering if applicants in general should raise these kind of disparities in pay, even if there is no bargaining power on their side, and not fear being seen as greedy or unrealistic?