I've fixed cars for quite a time. I'd try online breakers, auction sites and the main dealer. I used to buy from breakers in the EU, but many now exclude shipping to the UK. I've been lucky enough to only need 1 piece of trim since I've had my Civic. The local main dealer had the best price. Trim was new, included all the clips and cheaper than s/h from online breakers and the auction site. It still wasn't cheap, but that was a shocker. Most of the local breakers here have closed and the one that remains only deals with the public mail order. Of course you could post a wanted list on here - but that's obvious.