How old is your kid?

My dad gave me a broken Mac Plus and told me that if I could fix it, it's mine to keep. I swapped out the motherboard myself, at age 8.

Later on, my dad bought me an iBook G3. At age 15, I bought a class set of 20 iBooks and sold them to friends for $150 each.

http://peterburk.github.io/blog/#iBookRepair

Don't worry about their computer not being new/fast enough. They'll figure out what to do with it to push it to the limits. Please do give them root access.