Does having better degrees/certificates make such a big difference in terms of salary?
Thanks!
Can’t hurt to ask and negotiate.
Ya, it could.
be careful how you word things 
Yes.
If you want to be paid as much as them get your Masters. But then if you have your Masters, you should really go for a job you can’t get without it.
It is a culture that has been about passing tests and getting qualifications for millennia. You may be better at singing Barney, but without the paper, you will not make as much.
I literally just approached my principal about exactly this, only opposite you. I’m licensed in TESOL and teaching Mandarin, but our school is an experimental school and they want a different certificate for the teachers who are paid generously. But I’m the EFL teacher, and I have the education and qualifications to do that job well. But they offered me something close to a cram school salary while other private schools like the one one I’m at pay easily 2x more for the work I’m doing.
Qualifications do make a difference in pay, especially with regards to masters degrees and licenses. Now, if there’s a gender pay gap and all other things are equal (same experience and education level), that’s not legal under the LSA. But if you’ve got a BA and your coworkers have Masters, that’s standard.