Over on the UKWorkshop forum Dibs-his getting together orders for a members Router plate that will cost under 20GBP it will be 6mm Ali with center rings.
http://www.ukworkshop.co.uk/forums/viewtopic.php?p=416831#416831
http://www.ukworkshop.co.uk/forums/viewtopic.php?p=416831#416831