It is also a bit of a myth that fares in the UK are always more expensive than those in Europe.
For example Paris to Strasbourg and London to Manchester are reasonably similar in terms of journey times.
So someone turning up at the Gare De L'Est without any advance booking this afternoon and wanting a full fare single (Plein Tarif Loisir) for the 13:25 to Strasbourg could expect to pay 89 (approx. £74.10). This ticket would only be valid for the 13:25 train, although it would be possible to exchange it for a seat on a later train. Subject to space being available of course, as TGV's are reservation only.
An off peak single from Euston to Manchester, again without booking in advance, is £73.20. This would be valid on any off peak train. Moreover, an off peak return is £74.20, whereas to come back from Strasbourg to Paris would require the purchase of an additional ticket.
Peak fares in the UK are of course much more expensive.
The point is that when comparing fares between countries you have to compare like with like, in terms of whether it is necessary to book in advance, whether the ticket is valid on all trains and the level of service provided.
To use my earlier example, there is generally one train per hour between Paris and Strasbourg, with occasional extra trains plus some examples of 90 minute gaps in service. Whereas between London and Manchester there are three trains per hour for most of the day.
Anothe comparison made in last mights program was the cost of season tickets between Woking and London compared with similar journeys in France, Germany, Spain and Italy. The UK season ticket was most expensive, but it would be interesting to compare the level of service provided between Woking and London compared to the level of service in the other countries.