I don't think £175 is too bad for a good quality dress that you will immediately get two wears out of. It's a classic cut so I'm sure it will do you for a few more events if you look after it. I still endorse the defluffing costs too. You want to be special underneath as well as what's on show.
Plus you never know, you might get lucky....
And we'll hear no more negativity thank you. There's ebough people who will do you down, don't do it yourself.
Seriously if you're getting double whammy two days running then buy the dress AND have the beauty treatments. Veet stinks and neither thst nor shaving have the same results as a good wax. You only live once. Get out there.