Background:
My coworker and I got hired full time at the same time (around 3 months ago) to make video and photo content for a university. I got this job as my first full time videography gig following years of freelance content creation work. His background is as a literal videographer and he runs his own videography business.
When I interviewed, I asked the upper-boss immediately about a pay bump seeing that 20/hr (41k annually) is significantly lower than other nearby universities/roles of this kind (50k is pretty standard starting pay). My boss' answer was a hard no at the time, but I obliged and took the role anyway because I wanted this job and I can still live off this wage.
So flashforward to today and I find out my coworker is leaving in a month to pursue his videography business instead. I think that it makes sense: why wouldnt you pursue your personal passion? And although I wish I didn't have to pick up his extra work (we're a small team), I support the idea of self-autonomy.
BUT I also found out when he got hired, he was gonna walk out unless he made 50k. That's 10k more than me, and only 5k less than my manager (who's been here for 12 years). Apparently, when he asked for more, the upper-boss made some moves and found 10k more budget for hiring him. I'm kinda pissed and now that he's leaving, I think it's the perfect time to leverage myself and get a paybum, especially considering we have the same quality of work.
Now, dont get me wrong, things have been great. I love my work, my coworkers/manager, my environment – everything is great. Even my boss is a pretty good dude and I enjoy working under him.
TLDR: coworker got an offer at 10k more than me for the same work but now he's leaving after only 3 months.
How can I strategize a raise here?