fyi it is a similar diffuser if you had your heart set on that particular one in the original post. The mature diffuser is a bit larger and covers more bumper, the trademe link is a replica hks kansai diffuser. (both good lookers imo) I think you will have to look on ebay for replicas, around $250 for each pair (skirt, lip pair, rear spats) so about $750nzd with I'd expect $500 shipping, yeah that's the killer. There are nz sellers such as fortyone who can sell you the oringal chargespeed kits for $2000!,
search ebay for 04 bottomline, might find the frp kits alot cheaper than the carbon fiber.