For a multi-country Asian SIM card I'm not sure you how you beat the AIS SIM2Fly. It's coming in at $2.50 per GB in 20+ countries (4GB for $10), it's reloadable, does voice and SMS if needed.

That means Google Fi and Gigsky are 300% more expensive and T-Mobile is 180% more expensive per GB.

SIM2Fly Asian plan price applies to:

1. Australia
2. Brunei
3. Cambodia
4. China
5. Hong Kong
6. India
7. Indonesia
8. Japan
9. Laos
10. Macau
11. Malaysia
12. Myanmar
13. Nepal
14. Philippines
15. Qatar
16. Singapore
17. South Korea
18. Sri Lanka
19. Taiwan
20. Vietnam
21. Tibet

Then if you want to use the SIM2Fly worldwide (80+ countries) use the worldwide plan which comes in at less than $7 per GB. It's now also sold as an eSIM, ( https://esim2fly.com/ ) so get it anywhere you get email. If you keep the SIM2Fly valid and active, you can use it for years, topping up and adding plans as needed.