Here are some inexpensive Holiday gifts for everyone on your list. Everything is $40 or less and many things ship for free! For a look at gifts for kids, check out the Toy Gift Guide!
Lillabo 20-Piece Train Set - $14.99 from IKEA. These wooden trains and train tracks fit with Brio/Thomas the Tank Engine pieces, so it's a great (cheap) way to complement an existing set.