I now have a dress for my cousin's wedding. It took me 3 shops and 50 minutes and cost me $40. I have definitely broken my own record for quick and cheap, and it's actually something I like - not a desperation buy.
I haven't taken a photo because it needs shortening. But it's a black maxi dress with a deep V neck at front and back, and shirring just under the boobies, in a cotton/viscose/lycra knit which drapes really well without clingy to anything dodgy. I'll have to be careful with the hemming because I have ruined knits in the past when the presser foot action has stretched the fabric out and I've ended up with a rippled and warp hem. So I may even do it by hand.
Funny, I always thought a long dress would just make me look like one of those Greek columns you see holding up banks (or perhaps a hot water cylinder with arms and head). I'm quite happy with this one, and the boy is too.
*Also known as the House of G - it is THE place for cheap 'n' cheerful women's clothing.