A candidate gave a price bracket for a role he was put forward. For the sake of the argument let's say he mentioned minimum 80k per year.
After the interview, he found out that the role was actually far more complicated than the one that was described and was sold short. He mentioned that to the recruiter.
Eventually he got an offer from the employer (via the recruiter) for his minimum stated salary of 80k.
Since he stated as "minimum 80k" and found out that the role would be a more complicated/senior one, and given that he has been told that he the only one who could progress through the interview stages, isn't it prudent to ask for at least 10-15% more? I suppose compromise shouldn't be an option since eventually he would not be satisfied with his remuneration given his responsibilities.