Here's some sample pricing for Leeds to Manchester next Tuesday night, 16 July. It is admittedly July but will mostly not be during the school holidays, and there's no obvious evidence of a large event in Leeds.
TP 1939 £13.90 *
NT 1939 £4.50
TP 1950 £11.80
TP 2007 £13.90
TP 2018 £11.80
NT 2018 £4.50
NT 2021 £4.50
TP 2034 £11.80
TP 2039 £13.90 *
NT 2039 £4.50
TP 2105 £11.80
NT 2118 £4.50
NT 2121 £4.50
TP 2134 £11.80
TP 2139 £11.80 *
NT 2139 £4.50
TP 2205 £11.80
TP 2216 £11.80
NT 2218 £4.50
TP 2234 £11.80
TP 2240 £12.80 *
NT 2239 £4.50
TP 2303 £11.80
TP 2335 £14.90
TP 2340 £12.80
TP 0008 £14.90
*TransPennine Express stopping service (incl. Mossley, Stalybridge)
The walk-on single fare for these services is £21.90 (or £17.40 for Northern Only). Even if one were only going one-way, on a relatively quiet train at one of the least busy times of the week, you would not be making a great saving from committing yourself to any of those TransPennine Express trains. Of course as with most routes, the walk-on single fare is a rip-off, and the return fare at £22 is the more likely comparison. As you can see, every single Advance ticket TransPennine Express are selling (on the quietest trains) is more than half of the cost of a return - making it near certain that a return ticket will be cheaper. A period return is only £1.40 more than a day return, so even if one were staying overnight, one would almost certainly find a return ticket cheaper than a pair of Advance tickets.
This is what
@yorkie was talking about. These TransPennine Express Advance tickets are a
rip off. There are only very limited circumstances where someone would actually be better off buying one. TPE are doing very little to encourage people to travel at quieter times. The Off Peak tickets in question do not have afternoon restrictions, so it is far more likely that people will just travel whenever they want, rather than waiting for these post-peak trains which have a few empty seats.
Northern have sensibly identified that trains leaving Leeds at 9pm Tuesday will have a low load factor, and reacted accordingly to this by cutting prices. Hopefully this demonstrates my above point as to why I usually end up giving them my business now.
It's also noteworthy that in May 2018, TPE significantly expanded their number of evening departures from Leeds to Manchester. There used to be a 2141, 2209, 2241, 2309, 2335 and that was it. Look at it now!