Night trains

James, I haven't checked, but I doubt that you'll find "cheap tickets" for those two routes. Those are long trips, and especially if there are any changes during the night, you won't get much sleep. I'd consider budget flights on those routes, as they'll likely be cheaper (depending on which date you'll be travelling). For example, EasyJet has flights from Paris / CDG to Barcelona / BCN for €57.99 on 6 June. RyanAir flights may be cheaper, but they use somewhat "remote" airports so you'd need to include the time and cost to get to and from the airports at either end. For travel from Barcelona / BCN to Milan / MXP, have a look at Vueling. Again depending on which day you're travelling, they have flights listed as low as €34. One point to note with budget airlines, is that they often use a "sliding scale" so the prices will increase as the flight fills up. Tickets are usually non-refundable and non-changeable once booked. Finally, the baggage limits are usually somewhat restrictive, and only ONE carry-on item is permitted. Happy travels!

tgv-eurpe.com has restricted tickets for six-berth couchettets for 79 Euros; which IMO is quite reasonable. If you are looking for a private sleeper they are more expensive, check raileurope.com for prices. For more info head to this excellent site: http://www.seat61.com/Spain.htm#Barcelona It's a direct train so you should sleep well.

RENFE, the Spanish rail site, has promotional fares of 115 euro per person in a private double sleeper for both of those journeys in May. The Barcelona to Milan only runs on certain days of the week. They haven't posted fares for June yet. RailEurope charges $343 per person for the same thing.

Has anyone bought night train tickets off eurorailways.com? They seem to have the best prices? Is there a catch?