I will reiterate what I said on the IIM A group since I have received many DMs related to candidates already earning close to median salary in these IIMs.
This is my opinion and from what I have seen with my peers and those i have helped in the last few yrs. For those already earning close to 18-20 lpa, their immediate post mba salary might be a little disappointing, however, it becomes much easier to increase and sustain a higher salary (than without an mba).
Good resources in Tech (engg manager types) might not follow this trend though, since tech salaries are anyways high.
Also it is imp to evaluate if you already see a pathway to get from here(20-30 LPA range) to 70-80+ lpa in the next 5 yrs. If you can see a clear path, then don’t go for MBA.
If you don’t, then evaluate how Mba can push you to higher earning roles and help you sustain these high salaries.