I've been waiting for a set to drop below $20 and spotted this on Kogan. I've usually seen this set retailing between $35-40 at other places. Requires one C battery.
Copy pasted product info below:
This exciting toy rollercoaster provides endless fun – well into the night!
DIY construction – a rewarding challenge!
Unique glow in the dark design
5m of exciting track length
Elevator keeps the rollercoaster moving
The 5 included marbles can perform 360-degree flipovers and incredible steep drops
The DIY Glow in the Dark Toy Rollercoaster is bound to delight children and adults alike. Enjoy the challenge of putting it all together, with the end result being an impressive rollercoaster set that you can be proud of!
Since it glows in the dark, this rollercoaster set can be enjoyed with the lights off, and comes equipped with an elevator that takes all the pieces from the bottom back to the top in a continuous loop.
It's $1 cheaper if you don't want to play in the dark
https://www.kogan.com/au/buy/diy-toy-rollercoaster-5m-b/