Yep the cheaper the tickets, the more restrictions. We're currently living near Southampton and wanted to goto London, however searching all the train websites came with very high prices and no real deals or special offers on any day. The cheapest I was finding was about 40 pounds per person return, and we were willing to be flexible etc etc. Anyway I had just about given up when I decided to look at the option of catching a bus, so went to megabus.com and searched, and ended up on the megatrain website which I didnt know even existed and booked a return ticket for 4 pounds each. When I looked up the service, it is actually offered on a 'South West Trains' Train, so is the same train as being offered for 40 quid return on thetrainline.com ..... But the price doesn't appear on any of the search websites.