Quoting "£200-400" means nothing to us if you don't tell us the original price. A train from Aberdeen to Cornwall I'd expect to be about that price, for example.
Plus, are you using the same conditions? Looking to book the same time in advance, same type of ticket, etc?
Try using the find cheapest fairs option. It might mean you're on a slower train though.
And get a 16-25 railcard if you're going to be doing a lot of train journeys.
Get a railcard and book your tickets smartly - in Scotland tickets are cheaper to buy in the ticket office, also if you're not too bothered when you arrive you can get some deals by avoiding peak times.
I think they have, especially on London Underground.
About 5 years ago if I forgot my oyster card it cost me about £0.50 to get to school.
Now it costs £2.00. And that's for a <5 minute journey! And that's only the child fare!
in july it cost me four pounds for a single journey into town.... this week it was 6 :|
Are you sure that you just aren't confusing the different ticket types?
Perhaps the tickets you bought beforehand were "advance" fares (which are cheaper, but only available before the day and they limit you to using the specific train you book on)?
£200-400?! I can get from Aberdeen to Newark for under a tenner, and that's well over 400 miles...
Try the individual train company's websites instead of using an overall site, book at least a month in advance, use a railcard, and there's usually an option for "cheapest journey" that may take you via a slightly longer route but for less cost.
Where are you going if it's costing you over £200? I'm going home to Birmingham from Glasgow in a couple of weeks for c.£15. If you book early enough, have a railcard and aren't too restricted by time then you can often find decent prices. It can get ridiculously expensive, but I'm sure if you shop around you should be able to save some money.