Thailand Bullet train project vs India Bullet train project

bangkok to Nakhon Ratsachima distance is 260 km
Total cost of project is US 5.5 bn dollar
To be built by Chinese

Ahmedabad to Mumbai distance is 508 km
Total cost of project is 17 bn dollar
To be built by: Japanese

What can explain -  1.5 times expensive cost for India?


Sources:
https://www.ndtv.com/world-news/thailand-approves-5-5-billion-bullet-train-project-with-china-1723904

http://m.indiatoday.in/story/thai-bullet-train-cost-prashant-bhushan-apologise/1/1060012.html

https://en.m.wikipedia.org/wiki/Mumbai–Ahmedabad_high-speed_rail_corridor

http://shanghaiist.com/2017/08/21/china-thailand-rail.php