Powered by 4 built-in button batteries, Package Contents: 1x Inductive Toy, 1x Marker Pen, 1x Paper, 1x English Instruction, 1x English Colorful Box.
Price history, coupons and price alert are available on this page. Best price?
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
1. ($15.19): 00c906
coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): 13f142, AFfbG10, BGMPB2020, BGAFF10OFF, bGhOnEy10, BGdragonBoat, bgshOOp10, BGRC902, BgoFErTaSchInA10, BgcLuBofErtA10, BGCuponation10, BGHONEY2110, BANGGOODSD, BGc7b765
(there’s a little possibility that old coupon will work)
Price history and price alert
Check out price history chart (for all/most countries) for Marker Line Inductive Vehicle Toy. The lowest price was: $2.99.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).