In reply to Alan M:
"Manchester to Belgium return including hold luggage £60
Train Liverpool to Derby return £50 (off peak travel)"
That's a classic example of my point.
Here are the train fares for Liverpool to Derby (ignore the silly ones at the bottom, £999.99 is normally used to prevent a fare being sold, not because it would actually be sold for that, though it doesn't stop the Press liking these things).
http://www.brfares.com/#!fares?orig=LIV&dest=DBY
You will notice there are no Advance fares. So everyone who travels (let's ignore single fares, Railcards and child fares to keep it simple as these don't detract from my point) pays either £49.20 or £63.40, the latter being if you have to go before 9am or if you really want to dawdle and take 5 days over your outward journey.
So let's take a typical off-peak train you'll use for some of the journey, 4 coaches, about 75 seats per coach, 300 seats total, let's say it's full, let's say everyone's doing the same journey. The railway gets £7380, and the same again going back.
Let's now take an aircraft of comparable size operated by a low-cost, an A330 would seem to fit the bill (yes, I know most low costs use 200 seat-ish aircraft, this again doesn't detract from the point). They would yield manage along the following kind of model:-
First 10 seats £1
Next 10 seats £2
...
Last 10 seats £500 (or something)
They still get their £7380, and the average fare per seat is still £49.20, but instead of everyone paying the same (near enough), some people get a very cheap deal and some get a raw deal.
Some train fares work a bit like that (e.g. on InterCity routes) but that's only the Advance fares - the legally-regulated Off-Peak fares top these out to the point I almost never find them worth buying.
Hopefully that makes sense. The other thing to watch out for with the railway is that advance fares are usually only released a month or two in advance of travel, so you can end up paying more if you book *too* far in advance. brfares.com is useful because it means you can check out if there *would* be any.
This being the case, I'm surprised you bothered booking that train ticket in advance, when you could have rocked up to the ticket office and bought it on the day.
Neil
Post edited at 23:48