Well it can put you at a disadvantage. We do live in a meritocracy, and one of the basic ways we judge each other is through salary. having such a low salaryis not a "problem" per se... meaning if you have done other great things in your job it shouldn't really harm your application, but the AdCom might wonder why you remained and did not move on, their logic being "if you were so good, why didn't you get more?" and usually the best strategy to take here is to nip it in the bud by addressing the issue explicitly in one of your essays.
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