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if I book FR for 60 euro each way but then decide - actually I don't want to return, I'll book when I get over there or whatever, I pay 60 euro for my one way ticket. [okay there is the 4 euro CC charge or whatever, but that's a small thing compared to...
if I am booking my 99 euro "each way" return to DUB-JFK - admittedly a steal[flyaerlingus.com], this turns into 715 Euro if I book one way only DUB-JFK on the same day and sector that costs 99 return!
If there is no punishment for not turning up for your return flight, why would anyone ever pay a "full-service" one way fare?