From London Marylebone through to Birmingham Snowhill (sometimes beyond that to Stourbridge Junction too).
Off peak during weekdays, but available at weekends for most train journeys.
Yes, there are some engineering works at present at weekends which are impacting the prices of the reverse journey - from the Midlands through to London.
Takes under 2 hours to get to Solihull and a few minutes more to get to Birmingham itself.
This price also applies to stations in between such as Banbury; Leamington Spa; Warwick; Solihull etc
It's £5 single for normal people.
If you have a student railcard then it's £3.30.
I rarely see an inspector on these off peak journeys and when I do, they never seem to focus (I've accidentally given them old tickets to check and only realised much later on). Not that I am trying to encourage anything here as £5 for normal people is cheap enough without having to pretend to be a student to get another £1.70 off.
Anyway, a good use for this could be where you travel back home at weekends and rent in London during the week while studying at Uni or working etc £5 tickets are always available for use on trains departing Marylebone at 9pm and thereafter. Under normal circumstances (i.e. no engineering works) £5 tickets are available for almost every train coming back down to London on weekends.
Not as fast as Virgin Trains, but a lot cheaper.
You will probably need to book at least three or four days before hand (I book a week in advance personally and always find tickets available on the London to Birmingham journey). Otherwise the prices are a tad higher (like £7.50 for normal people travelling with 2 days notice - less for students.)