I'm glad to hear that your son enjoys building models! It can be a great way to encourage creativity, problem-solving, and fine motor skills.
Personally, I used to buy kits for my kids , but as they got older, we started making our own custom projects using reclaimed wood, cardboard, and other materials. We even had a "maker space" in our garage where they could freely experiment with various crafts. It was amazing to see their imagination and creativity shine through in the process.
If you're interested in creating similar experiences for your son, you might consider trying hand-crafted kits made from everyday objects like cardboard tubes, paper rolls, or craft wood scraps. There are many tutorials online that can guide you through making your own model-building materials.
That being said, a mix of store-bought and DIY projects can work well too! If your son enjoys the pre-designed aspect of building models, purchasing kits from retailers could be a great way to provide access to new designs and structures. You might want to explore other hands-on activities that combine creativity, imagination, and practical skills like woodworking, masonry, or even cooking/baking – anything that allows for experimentation, trial-and-error learning, and sharing results with others!