Particulate Filter Problem

[biper]

Hi, has anybody had any experience of these, it is on a Pug 607 but I understand that they are fitted to most Pug & Citreon models. Anyhow it would appear that mine is now in need for renewal. I have been quoted upto £600 at my local Pug dealer, they have you over a barrel as it needs some fluid adding at £20 per per Ltr (5Ltr) that only the main dealer can supply and a new filter at £200 plus a diagnostic test and reset. Plus labour at £77ph and of course all plus VAT.
Has anyone had this problem and is there a way round it, can this filter be bypassed or will it mess up the electronics.
Thanks in advance for any constructive comments/suggestions.
biper