How Reliable Is the NPC of the Colleges Meeting 100% Financial Need?

Recently I did the NPC of many colleges that claim to meet 100% financial need. Most results include the Federal Pell Grant of $5,700. However, I don’t think I qualify for the Pell Grant since my sibling (a rising junior in a college that meets full financial need) has never received any $ from the Pell Grant. In my impression, Pell Grant is for the most needy students. Our family income is in the range of $70,000-80,000. Could I make any mistake in the NPC? What amount should I put for the tax my parents paid? Their tax should be about $5,000. With some tax credit, they actually paid about $1,500. Should I enter $5,000 instead of $1,500? Otherwise I don’t think I make any mistake in the NPC questions.

I also notice that most of the schools (meeting full financial need) give me the same FA, disregarding my sibling is in college or not. This is different from the results I got when I tried the NPCs in January.I know the College Board NPC has been updated by many colleges recently. Each school I did twice, with a sibling in college and without. How come that many schools don’t distinguish the two situations? I’m pretty puzzled. My counselor told me the EFC would be reduced to 50% when my sibling is also in college. However, I only see about $1,000-2,000 difference or no difference at all.

BTW, my sibling goes to a college that claims its NPC is very reliable and it is (from my sibling’s experience). It gives me an estimate of FA without Pell Grant and the net cost is about 60% of my sibling’s plus $2,000 student contribution. However, our family isn’t sure if this college would be willing to give two huge financial aid packages to our family if I am admitted. (I have similar stats of my sibling.) This college meets 100% financial need of admitted students and admits that it is need-aware toward the bottom 10-20% of the students qualified for admission. I am not sure how strong an applicant I am in its pool.

Any insight, advice, or experience on NPC and colleges meeting full need is highly appreciated.