Those wooden Thomas the Train items are about the only thing I saved from my sons possessions when he was young. They're still in good shape and hold their value well not that I'd sell them. He can use them for his kids one day. He can have everything but the train table - I used that to hold all my power supplies, controllers, etc for my layout. He quickly graduated to real trains but like most, lost interest around 7 or 8. Fortunately, we share common interests in other areas and as friends have commented, continue to share a close bond into his teenage years (17 in March).
-Greg