Eurorail from London - Paris
 

I will be traveling to Paris via the Eurorail. Do I need to buy the tickets online? Or could I buy them at Waterloo station the day before departure? Will there be a price difference? Thanks in advance for your help!

It's the Eurostar.

Buy them in advance over the website as the difference can be as much as £200 per person

If you can buy far in advance on the Eurostar web site, you can safe a huge amount. You pay a high premium for booking a same-day trip at Waterloo.

Thank you! ( I meant the Eurorail website..sorry for the mistake) I will purchase them right now.I appreciate your respone very much!

Cheapest single ticket is €67 if you book as an American via www.eurostar.com

I'd also learn how to clear the Eurostar cookies and get the prices for your whilst pretending to be British or Belgian - note however that whilst Americans can book 9 months in advance, Europeans can only book 5 months in advance

And return tickets can be cheaper than some single tickets and there's no problem in not using the return leg

You can also buy them from rick steves travel store:

http://www.ricksteves.com/rail/rail_menu.htm

The benefit is that he will actually UPS you the tickets right away as opposed having to pick them up at waterloo station.

I bought mine there and just received them. I crossreferenced with the eurorail sight and the prices were the same (plus a few bucks for ups). We paid $244 for 3 tickets (1 youth) from london to paris in may.

Oops, just wanted to add...
When you buy from rick steves you also get a onetime 20% discount towards any purchased made in his travel store (bags, books, etc).

Actually I just opened my ups envelope now and they also sent me: a eurail timetable, europe planning map, and rick steves travel skills dvd (!)

I can't think of a reason not to buy through his store. Having the tickets before I leave also gives me some piece of mind...

I would actually feel SAFER to pick up the tickets at Waterloo. At least you don't have to worry about losing/misplacing or forgetting the tickets at home. You pick it up from self-service machines. No need to queue up at the counter.