It's a fair question, but the honest answer is that there isn't a "typical" retake improvement that will tell you much about your own situation, because score gains aren't really a function of retaking — they're a function of what you change between attempts.
Here's what I mean. Your score is a reflection of your current skill level. If you take the test again without meaningfully changing your preparation, you'll likely land within a narrow band of your first score, because nothing underneath has changed. The test is just measuring what's there. People who retake and see little or no movement usually fall into this category: they did more of the same kind of practice, sat the exam again, and the number reflected the same underlying skills. So when you see retake averages floating around, they blend together students who genuinely rebuilt their skills with students who simply showed up a second time. That average won't predict your result.
So is 50-60 points achievable? Absolutely — and to be direct, from a lower starting point, where there's a lot of room to build, that's often a conservative target rather than an optimistic one. I've seen students improve far more than that. But the gain comes from the work between tests, not from the retake itself.
The more useful exercise is to figure out exactly what held your first score down. Was it a shaky grasp of fundamentals in certain areas? Specific question types you couldn't handle consistently? Timing that fell apart under pressure? Get specific, because "I need to score higher" isn't actionable, but "my accuracy on medium Quant questions is inconsistent, and my timing collapses in the back half of the section" is something you can actually fix.
Then build those skills up deliberately, and let your practice tests tell you when you're ready. When you're consistently hitting your target score under realistic, full-length conditions, that's your signal to retake — not the calendar.
Don't ask how much people improve on a retake. Ask how much your skills need to improve to reach your target, and then build to that. The score will follow.