Eurostar Booking from London with a foreign address ;-)

There was an article in the Sundays about the 'pleasures' of booking
using Eurostar.com (and a page on the Man at Seat 61's site) and
selecting Spain or Germany as your country of residence and being
offered a completely different set of tariffs (much lower) to
eurostar.co.uk, including cost effective single tickets rather than
their £155 flexible single, which is all you get if you try
eurostar.co.uk.

I followed all the tips about deleting your internet history/cookies/
files etc and indeed, it did come up with a 'Which Country are you
resident in ?' screen. Whichever country was selected seemed to bring
up the same set of fares (albeit priced in €s rather that £s). I'm
wondering if the site now detects where your ISP is based and prices
accordingly.

Do I therefore conclude that either Eurostar have closed this
particular loophole or at least done this in countries whose ISP it
detects as being British ?

I have a low cost German dialup number which places my residence in
Wiesbaden I shall try out.