Rich
I do not think it was a one off price although I did have to 'import' then from a Scottish BMW dealer (tip came via fellow BM3W member) as my local one in Chester was trying to charge me hundreds of pounds more for the same item!
I would have a quick chat with Mark_csl as he is usually able to get OEM BMW parts at a good discount and he has always been good to me when passing the discount on!
Hope this helps
Nick