It's not as cheap as those kits but this one proved to be a lot of fun for my niece.
She is 14 and hopefully will stay a nerd.
I lent tools and test equipment but she built and solved it herself.
Electronic Education DIY Kit “The broken code lock” (Troubleshooting Project)
A DIY soldering kit with “integrated” design flaws. Understand the working principle, find the mistakes on the PCB and in the schematics, and make it work.
CANADUINO® (www.canaduino.ca)