i don't know which country you are from. Thrift store sometimes have used thomas and accessories. I go to Value Village to find them. I believe in the US and Australia, Value Village is called Value saver or something like that.
My Trackmaster/Tomy/Plarail Photo Gallery Page (over 600+ photos and still under construction)
https://www.flickr.com/photos/183311600@N03/
https://www.flickr.com/photos/183311600@N03/