Money / 6 min read
Pay as you go versus data bundles
Every travel eSIM seller lists a price per gigabyte, and almost every buyer compares those numbers directly. It is the wrong comparison, because a bundle charges you for gigabytes you may never use and takes back whatever is left at the end of the validity window.
The number that matters is cost per gigabyte actually consumed.
Where the waste comes from
Bundles are sold in fixed sizes with a fixed validity, typically five or ten gigabytes over 30 days. Data use on a trip is lumpy and unpredictable: heavy on travel days, near zero on days spent somewhere with wifi.
Buyers respond rationally by over-buying, because running out abroad is worse than overpaying slightly. The seller's margin is built on exactly that asymmetry, and typical utilisation on travel bundles sits well under three quarters.
Doing the effective cost
A five gigabyte bundle at twenty five dollars is five dollars a gigabyte on the label. Use three and the effective cost is eight dollars and thirty three cents per gigabyte consumed. Use two and it is twelve fifty.
A pay-as-you-go balance at two dollars a gigabyte is two dollars a gigabyte whether you use one or nine, and the unused portion is still there in six months. The setup fee is the only fixed cost, and it is charged once rather than per trip.
- Bundle label price is a floor, never the real price
- Divide bundle cost by gigabytes actually used, not gigabytes bought
- Expiry converts unused data into pure margin for the seller
- Pay as you go removes the forecast entirely
When a bundle is genuinely better
Very heavy, predictable use in a single country. Someone who will certainly burn thirty gigabytes in two weeks in one place can often find a local bundle cheaper per gigabyte than any roaming rate, and should buy it if the registration requirement is acceptable.
That is a real case and it is worth saying plainly. Pay as you go wins on flexibility, multi-country trips, light and medium use, and anything where the total is uncertain. It does not win on raw volume in one market.
The hidden cost of expiry
Expiry is the quiet part. A traveller who takes three trips a year and buys a bundle each time throws away the remainder three times. Over a few years that is a meaningful sum spent on nothing at all.
A balance without expiry changes the relationship. Credit left after a trip is not a loss to write off, it is the start of the next trip, which also means there is no incentive to burn data at the end of a holiday just to avoid waste.