TL;DR: how likely a company accept a counter-offer for a graduate role?

Hi, I'm currently in my final semester of my master degree in IT. One of my final courses is a project which is supervised by companies. My group's company stated that they could offer a position once the project has finished. And they have been doing it for 2 semesters. (with acceptance rate of 8/10 students got the position).

My friend has a acquaintance who got offered the position and worked there currently. He discloses the salary to us (informal while hanging out). I was not satisfied with the offer, but it's better than my current casual job.

the scenario below is not real as I haven't been offered the role as of now. But I believe that most of my group will receive it

If they are offering the same amount to me, I'm thinking to make a counter-offer which is 30% higher than their offer. However, this is a graduate position, so I don't know if it's possible at all.

I have some factors which can helps me (or not. I need guidance on this.):

1. While my technical skill is not as good as the supervisor who managed us, I believe I'm ahead of my peers. This is supported by having a relevant certification for the business that they're in, having to work casually for 2 years (20h p/w) in IT industry plus some freelancing before that, and by having worked with my peers, I can feel that I'm ahead of them.
2. I'm not in a financial crisis. I have a job which have 30% lower rate than the offer. And I'm confident that I'll be working full-time for my current employer. This way, I think I can find other opportunities later on without having to worry financially. **however, I believe that I can't learn much (relevant skills) in my current job.

However, there are some factors which can back-fire me (it's purely my opinion as well. So I don't know if it's relevant)

1. Technically I'm a graduate. And I'm working while studying so in the paper, it seems like I have a track like this: High School -> undergraduate -> postgraduate. However, I've freelanced while doing my undergraduate and I have a casual job (still doing it) while doing my postgraduate.
2. I'm afraid that as it's a graduate role, it's non-negotiable and all graduates will have the same salary. (at least in that company. Though this is just me thinking.)
3. They can see me as being greedy.

How likely will they accept my offer given above circumstances?