Start with the price per day, not just the headline price. The 1 GB for 1 day plan is $1.29. That is the cheapest option we sell and it is built for a quick visit, like a layover in Tallinn or a single day exploring the Old Town. You get a full gigabyte and you only pay for one day.
If your trip runs longer, the math changes fast. The 1 GB for 7 days plan is $1.29. That is almost the same price as the one day plan, but the data stays valid for a whole week. For a light user on a short city break, that four cent jump is the obvious pick. Always compare the daily cost before you buy.