Have you ever thought about combining Wooden Train Set and Duple? Here is DIY solution which costs £0
What you need is sharp knife or stanley and glue.
Cut the bits out of Duplo block. Don’t throw them!
When sticking Wood and Duplo together use a long block to set the distance between smaller blocks. Otherwise you might get in trouble when you try to build more complex objects.
Make sure you leave enough space on the “male side” of the wooden block. It comes handy when you pair it with “female”.
Tiny bits you cut off the Duplo block are great filler 😉
Job done! Enjoy you glass of Merlot, while your little one enjoys his/her upgraded set. You’re hero of the day!