Anyone can wear/tailor the clothes. It's just whether they look good in it.

By the way, I think you have the link a little off...rozen instead of rosen?
And yes, the money. It's quite a bit of money.

A rudimentary calculation of Barasuishou's dress (probably not including shipping etc) brings it up to almost 250AUD. Still less than some ebay I've seen, but well.

Obviously not coming straight from the manufacturer.
Oh my gosh, guys doing Rozen Maiden cosplay. -snorts-