Perhaps for me it's a holdover from Halloween, but I think part of the fun of tango is the dressing-up part. When I took belly dance classes, I had all kinds of harem pants, silk tops, coin belts and finger cymbals and scarves and veils. And the henna kit for the do-it-yourself henna tattoos on the hands.
When I joined the Stanford Fencing Club (a short-lived pursuit due to tango conflicts), I immediately ran out and got my own foil, padded jacket, glove and mask (there is nothing grosser than borrowing someone else's fencing gear and still-damp-with-sweat face mask).
And when I started dancing tango, I began to amass a collection of clothes that ultimately grew into its own tango closet. A closet with a life of its own. When I would go shopping, I'd compartmentalize what I saw into either, "Gee that would be fun for work," or "Boy that would be great for tango!" If I had to choose, the tango outfit got purchased first. You want to be prepared for every mood on dance night, right?
Le Chemin du Tango has an interesting observation on how we dress for tango. I'm much more casually dressed for a milonga than I used to be, except for the shoes, of course. I dressed up a lot more in Buenos Aires because I felt I could get away with it. Lots of my tango clothes now just hang out and wait.
And oh boy, here at the office, the UPS guy just delivered my new swing dance shoes and skirt that I ordered online. I'm dying to go into the bathroom and try everything on but the pleasure must be delayed until I get home...