It might also be worth looking at Sunpak stuff. I believe they are sub-contract manufacturer's for Canon, Sony and Pentax (certainly true) flashguns. There is an uncanny similarity between the Pentax AF540 and the Canon EX530.
http://www.microglobe.co.uk/catalog/...acturers_id=56
As you see, the sunpak stuff is considerably cheaper than the OEM brands. I'd still go for Metz though.