I'll be going on the Eurostar (London/Paris and back) Oct 6-16ish. I can book ahead for $86 round trip...or wait until my plans firm up....but I figure if I show up and buy a one way the day I want to go, and another one way the day I want to return....it will be really, expensive (like airlines). I wanted to be flexible, but not sure how...any ideas?
Cheers!