chunnel pricing in advance

Yes, the less expensive tickets tend to sell out earlier.

Eurostar tickets go on sale 6-9 months ahead (sometimes 11, check your dates). They definitely get more expensive closer to travel dates. In high season, weekends, or holidays you may be well out of luck if you don't book ahead. Prices also vary by time of day and the day of the week.

Passenger trains between Paris and London are only provided at the moment by Eurostar. They have a good webpage, and a similarly good app.

Other companies are hoping to provide a competing service in a few years but nothing is set yet.

All trains between London and Paris (and London and Lille, Brussels, and the Netherlands) use the Channel Tunnel. (we haven't used the term chunnel here for many years).

https://www.eurostar.com/uk-en . That link is set for UK, you can change the country by clicking on the Flag.

What is the Chunnel?
The Channel Tunnel (often called the 'Chunnel' for short) is an undersea tunnel linking southern England and northern France. It is operated by the company Getlink, who also run a railway shuttle (Le Shuttle) between Folkestone and Calais, carrying passengers in cars, vans and other vehicles.............
The Chunnel actually comprises three tunnels: two rail tunnels, used for freight and passenger trains, and a service tunnel.
https://www.eurostar.com/uk-en/travel-info/eurostar-experience/the-channel-tunnel

I often see some chiding ( some times very derisively) by those in Europe of the use of the term 'chunnel' by folks on this side of the Atlantic. The eurostar site for the US contains the above noted text. Eurostar is the one perpetuating the use of the term.

Nigel's comment was nicely done. ( per his usual) .

Americans use "Chunnel" because it was a catchy, widely used nickname in U.S. media during the Channel Tunnel's construction and early operation, combining "Channel" and "Tunnel" into a simple portmanteau that stuck in the collective American memory as the primary term, even as in Britain the term became associated with tabloid sensationalism and eventually faded from print.

Windyram, this American has never called it the "chunnel".

nancy, although prices generally increase closer to travel date as the lower fares sell out, occasionally Eurostar has a flash sale. Last winter I was able to save about £30 on my London to Paris ticket thanks to a poster on this forum.

If it’s the passenger train from London, people generally talk about that as taking the Eurostar or just the train to Paris.

If it’s the car transport, people will typically say they’re taking the tunnel.

If you don't mind the exact time of travel you can buy a Eurostar Snap Ticket. You choose to travel before or after 1pm, and are told your exact train 48 hours before departure.
Tomorrow (Saturday 31 January) snap tickets are available London to Paris for £70, but on Wednesday for £50. It can be as low as £35-
https://snap.eurostar.com/uk-en

Tickets for specific timed trains tomorrow are £208 to £224, on Wednesday £132 to £204, so that is a good price.

OK, you may end up getting up at silly o'clock or arriving at 11pm at night, so it won't suit everyone. However that is how to get a last minute bargain up to 2 weeks before travel. Snap tickets booked that close to departure are not always available at peak travel periods.

Thank you for the advice on EUROSTAR booking.