Help Me Build a Computer for my Little Brother

My little brother is your typical introverted kid. He enjoys his times alone, and in front of a screen, though that is not to say that he doesn't love his family. He loves us very much. He's quite a happy-go-lucky boy. His story begins in Puerto Princessa, Palawan, where my mother decided to adopt little baby Carlo from his dying biological mother. When Carlo got to 1st grade we started noticing that he had difficulty learning. We later found out that he has a learning disability and is on the spectrum. Carlo is nearly 10 years old now, and all he has wanted ever since he has discovered gaming channels with minecraft, turbo dismount, kerbal space program is a computer to play those games on. Help me make his dream come true this Christmas.