This site is useful and informative but I have a problem with their statement in bold. From what I understand, they use the cheapest plan that satisfies two conditions - it provides over 500MB of data and is valid for over 30 days. They present that this is the _best case scenario_. This is false of course, cheap plans have often a shitty value ratio. For example in France you can easily get 50G non-renewable contract for around 20-25 euros, SFR even offers 100G for 20. Maybe these are not the cheapest plans you can get, but they have much better ratio than what this site presents as a best case scenario for France (which is ~$0.1/MB)