I've only seen a finished one yet.
399 for such a solid trailer made of steel and spot welded is pretty reasonably compared to the other Tamiya trailers. But you really can't expect getting an already painted trailer for so little money. At least not one beeing made in Germany. It's quite labour intensive as you'll find out soon and it would only result in a price no one wants to pay.
Put it this way: Pretty good deal with the current exchange rate
