A couple more suggestions for you….
Firstly ,splitting your journey might be an option. Try searching for options to Manchester/Stockport and then a local trip onward.
As you’re returning on Sunday,check if Virgin do a relatively cheap on board weekend upgrade to first.
Sign up to Virgins newsletters,you’d be amazed at some of the exclusive offers chucked what you.
Finally you can save a bundle by bizarrely purchasing separate legs but staying on the same train. I’m sure it was Bath-Vip that posted a link to a website that does the work for you.
Hope that helps