When I was looking in to the big and expensive Lionel Scooby Doo train set models, I discovered a couple of other sets. All plastic, these look to be much simpler and cheaper. They also look to be a lot more fun, and have a good selection of accessories.
What does Scooby Doo have to do with railways ? Well, they probably appeared in a few episodes, which is enough of a link for most toy companies.
Boley - Where the action is !
The Cartoon Network - Scooby Doo ! Train Set came in '2 Assorted Styles - Collect Them Both !'. '18 Piece Playset - Wind-up Action'. Made in China. Copyright date on the box 1999. Since both sets use the same box, they have the same catalogue number - No.51103.
These were clearly aimed at younger children. The box says 'For Ages 5 and Up'. The front of the large window-box showed off the contents, while both sets were shown set-up on the back, along with a list of contents:
1 Mini Wind-up Train (it is a locomotive - two different styles - wind-up knob on the left side)
1 detachable trailer (they mean wagon or carriage, although car would be the American term - one is a small passenger carriage, the other looks to be a mine wagon - perfect for an old haunted gold mine)
6 piece self-assembled train track (4 curves, and 2 straights)
4 playscene accessories (plastic buildings)
2 paper accessories
6 figures - Scooby Doo, Shaggy, Fred, Daphne, Velma, and (I think) Scrappy Doo.
If you count the 'paper accessories' that is actually 20 pieces.
These were clearly not aimed at serious model railway enthusiasts, with wind-up engines, and plastic tracks. The accessories are great, and include the essential Haunted Mansion, Windmill, Water Mill, fountain with cherub, food stall, Railway station with clock tower, level crossing, and a single tunnel mouth, spread across the two sets.
The figures, tracks, and paper accessories are common to both sets. The trains and buildings are different. The colour schemes are a suitably spooky black and purple, with a little ghostly ectoplasm green.

All Four photographs from Worthpoint.
Paul Adams from New Zealand