purchase home from family

The house was given to my aunt and my mother from there father. My mother passed away five years ago, we had a living trust making me the executor of her estate. I have three sister that have a share of the house along with my aunt.
I house needs a lot of repair. My aunt wants to sell. I have made her an offer. She has ok the offer. Do I need to get an appraisal, I already know what wrong with the House. I will be paying cash for the house. Do we need to do a quick claim for all parties?