Regional vs global eSIM: which should you buy?
Buy as narrow as your trip allows: single-country plans are cheapest per gigabyte, regional plans (Europe, Asia) are worth the small premium for multi-country trips, and global plans only pay off for genuine multi-continent itineraries or frequent unpredictable travel.
eSIM pricing follows a simple ladder: the wider the coverage, the more you pay per gigabyte. A single-country bundle for Spain costs less than a Europe bundle, which costs less than a global one. So the buying logic is to match the footprint to the itinerary, not to buy flexibility you will not use.
One country, even for three weeks: country plan, no contest. The classic multi-country holiday (a Europe rail trip, an Asia hop): regional plan, because one eSIM crossing every border beats juggling three country bundles, and the premium over single-country pricing is modest at Airalo, Saily, and friends. Genuine globe-trotting (a conference in the US, then clients in Asia, then home via the Gulf): that is what global plans from GigSky, BNESIM, or a pay-as-you-go wallet like Roamless exist for; per-gigabyte they are the priciest tier, but one working setup everywhere has its own value.
Two checks before paying: the exact country list (regional plans differ on edge cases like Turkey in "Europe" or China in "Asia"), and whether your route's main country rides a good local network on that plan. When in doubt, narrow plus a small top-up later beats wide and wasted.