To auction or not to auction?

The price you see is the price you’ll pay - and more often than not it’s cheaper than buying a First Class ticket or upgrade directly, so you’ll still get a nice bit of saving as well as that plush First Class seat, guaranteed. 

All you have to do is click, purchase, and done - you’ve got your First Class seat. Make sure you keep hold of your original train ticket, as you’ll need both that and your upgrade to travel.