Therapy Cat Christmas

This is Oreo. I just adopted Oreo. He is a Christmas present for my elderly brother. My brother lost his home and his cats. He had to come live with me. He is financially and physically unable to live by himself. A co-worker is keeping Oreo for me until Christmas Eve. I have paid the adoption fees, bought litter, a pan, a collar, food and water bowl, a  bed, a pet carrier,  and flea treatment. I thought I had everything covered! I even had the $100 that I thought was the deposit. It turns out, the $100 is only a processing fee and my apartment complex requires another $ 200 for the deposit. A total of $300. I had hoped to give my coworker a $100 for keeping Oreo a secret for me until Christmas. I want to surprise my brother. He is 74 and has had cats all his life until he had to come live with me. His cats were his family. My brother has some mental health issues. He has no friends or other family he has regular contact with. I am doing my best to be able to keep him with me where I feel he is better understood and cared for. I hope to be able to do this for as long as possible. It is very challenging for me and I feel he will benefit greatly from the companionship of a pet. I am disabled and can only work part time as of now. I hope to be able to change jobs and work more or full-time after New Year's. The cat is going to add a bit more monthly expenses I think I can manage to budget in.  But I need some help to get this cat for Christmas without over extending my budget. I am trying to be responsible for myself, my brother, and this cat! Oreo is 4yrs. old. His owners moved & left him or he got lost. A neighbor took him to the animal shelter where I adopted him.  In a way, myself, my brother, and this cat have all been abandoned or given up on. I am committed to them with or without any assistance. I believe we can all do each other some good. Thank you any good you can do for us. It will be deeply and greatly appreciated.