AITA for refusing to give my brother an equal share of our parents’ cabin when he was never around to help take care of them?

I (34F) am the oldest of two. My brother Marcus is 31. Our parents bought a cabin on a lake three hours from where we grew up back in the ’90s — it was the center of every good childhood memory either of us has, and everyone always assumed it would eventually be “ours” collectively, whatever that meant.

Five years ago, our dad was diagnosed with early-onset dementia. Our mom tried to manage it alone for about a year before it became clear she couldn’t. I was the one who reorganized my entire life around it. I quit a job I liked to take something remote and lower-paying so I could be twenty minutes away instead of two hours. I managed their finances, sat through every neurologist appointment, moved my mom into assisted living after Dad got physically aggressive one night, and was the one who found Dad on the bathroom floor the morning he died last spring. Mom passed eight months later — I think, honestly, of a broken heart more than anything the doctors could name.

Marcus lives out of state. In those five years, he visited four times. He’d call our parents on birthdays. When I asked for help — even just splitting the cost of in-home care a few days a week so I could keep my remote job functional — he’d say money was tight and go quiet for weeks. I won’t pretend I don’t have feelings about that, but I also never sat him down and screamed at him for it, because I knew part of what was going on: his daughter, my niece, was born with a heart condition that meant two surgeries and a year of medical bills that I know for a fact wrecked them financially. I’m not a monster. I understood he was drowning too, just in a different ocean.

Our parents’ will, written a decade before any of this happened, split everything — including the cabin — 50/50. No updates were ever made once Dad got sick, because by the time anyone thought to update it, Dad legally couldn’t consent to changes anymore.

Now the estate is settled, and Marcus wants to either sell the cabin and split the proceeds evenly, or have it appraised and have me buy out his half at full market value — somewhere around $180,000 for his share. I told him I’m willing to buy him out, but not at full price. I told him I’d pay him $90,000 for his half, and explained that the other $90,000 is what I’m valuing five years of unpaid caregiving at, conservatively — the lost wages alone from the job I left were more than that. I told him I’m not trying to punish him, but I’m also not going to pretend the will’s 50/50 split reflects what actually happened in real life for the past five years.

He said I was putting a price tag on love and turning our parents’ deaths into a business transaction. His wife got involved and said I was using “guilt math” to steal from a man who was dealing with his own dying child during those years — her words, “dying,” even though my niece is fine now and has been for two years. My aunt, who lives near me and saw everything up close, thinks I’m being more than fair. Another cousin thinks family shouldn’t be assigning dollar values to grief and I should just split it evenly and let it go.

I go back and forth on this daily. When I’m calm, I can see that Marcus was fighting his own five-year emergency I had the “luxury,” if you can call it that, of not being in the middle of. When I’m not calm, I remember cleaning up after my father lost control of his body, alone, at 2 a.m., while Marcus’s phone went straight to voicemail, and I don’t feel like I’m asking for too much.

Update, two weeks later: Marcus called, not his wife this time. He didn’t apologize exactly, but he said something that stuck with me — that he knows he wasn’t there, that he’s known it the whole time, and that some of his anger at my offer is really just anger at himself dressed up as something else. We didn’t resolve anything on that call. He’s talking to a lawyer about “his rights under the will,” which I understand, even though it stings. I haven’t moved off my $90,000 number. Part of me wonders if I’m holding onto the cabin, and the number, as a way of making sure the last five years count for something on paper, since nobody’s ever going to put it on a plaque.