figuring out adjusted cost basis of selling inherited property

My brother and I inherited our father's property in 2011, appraised value for probate was $390,000 so my half of the fair market value was $195,000.  Brother died in 2017. House appraised then for $510,000. In 2022, I bought out widow of her half ownership, $275,000.  I made significant necessary repairs totaling $180,000.  In 2024, I sold the property for $788,000.  My selling costs were $53,318.  

1.  what is my adjusted cost basis to figure out capital gains tax?

2.  exactly where and how do I record this in turbotax?  Under investments, the only options are Proceeds and FMV at time of decedent's death.

3.  When I add the buyout, repairs, and selling costs, then subtract from the sale proceeds of $788,000, turbotax shows that I suddently owe $32,000 federal and $11,000 state taxes.  How can that be when the net proceeds are only about $134,000?  Our gross income is about $69,000.