Don't underestimate doing the towing test. It'll be a full day, if not two, at the minimum, I'd have thought. By all accounts it's not easy and really is a mini-HGV test.
I think you are looking at around £500 all in to do this, including the test etc.
However Joe, I'm keen to do mine at somepoint, so it may be that we could share the costs of an instructor/tuition and bring this price down if you were up for that. Depends when you want/need to have qualified by.
G
Depending on when and where I may be interested in splitting it three ways, if that would be wise or possible