$10,000 robot leggings

In 2009, Balenciaga rolled out "Transformer" leggings: made to order, from non-precious metals, at $100,000 per.

The OP predicted that this was destined to reach Topshop et al at a much more reasonable price in short order, but as far as I know, that hasn't happened (yet). Note that they'll likely be a pain to launder.

Transformer [Augustine Wong]

(via Wil Wheaton)