I believe both Eurostar and SNCF both had Sabre ELVA (American Airlines and later Sabre Holdings, beginning 1994,) design their RESARAIL 2000 system, so you can get a pretty good idea
why they have the range of charges and fares. The pricing is as discriminatory as any airline's - you pay the least for highly restricted, nonrefundable fares, the most - sometimes four times more - for changeable, refundable tickets usable at higher demand / peak days and hours.
I am glad to hear they did the right thing and allowed you to recoup your nonrefundable error fare.
Originally Posted by
Bacopa
Thanks everyone. I contacted eurostar, and they were gracious enough to refund my ticket even though the ticket was nonrefundable/exchangeable. I did, however, have to pay the current market price for the correct round-trip ticket. I think it's fair based on their (perhaps optimal) discriminatory-pricing scheme.