Yes, both ways would be £7.10. If you use the fare finder on this site it has the useful addition of a button to click to show the fares for the reverse direction. The peak times are not always the same each way.
Those times are pretty much in the middle of the peak periods so I can’t see any way to make a saving. I’ll hopefully hear back next week about the through fare and if it can be sold. It’s one of those oddities which is in the fare system but named underground stations are a bit of a problem.