Roamic

Roamic specializes in ultra-affordable eSIM access, with Vietnam plans beginning at just $2. Their unlimited data approach comes with a fair usage policy: you get full speed up to 3GB per day, then throttle to 1Mbps for the remainder of the day. This structure lets you stay connected at low cost while ensuring the network doesn't get overwhelmed by heavy users.

This suits travelers on tight budgets and those who don't need video streaming or downloads during peak hours. It's a good choice if you're comfortable with speed limits after hitting your daily quota and want the lowest possible entry price for basic connectivity.