Kids want to know about building games

Hi, my younger cousin is living with us and 12 through the summer. He wants to to use the free Unity platform. When he went to download it, he discovered he can't because the school district Chrome book doesn't allow him to download outside apps. My sister and I have want to pool our money together and get him a used laptop just so he can do Unity. He also said he's interested in learning about audio and mixing songs. He has an interest in game development from story boarding to creating soundtracks. I would say he is artistic, analytic, introverted, likes to build things. Anyways, can anyone recommend a computer system that would be good for a 12 year old for our needs? Used would be best.. anything under $200. I gave him my old monitor so he uses that with his chrome book.

/r/gamedev Thread