Affordable way to get BD imported to UK

An tips on getting shipments from Belgium or the Netherlands without crazy postage fees? I'm a Dutchman in the UK, with a big collection of Dutch languages BD, but I have many holes I want to fill in my collection and there is only so much I can carry on the few trips to the country that I manage to do.

Pretty much pointless to pay £2.99 for some secondhand BD and then to get slapped with a £15 delivery fee. Hahaha. Is there really no shop with better rates or some method I am not considering?

Also; Long shot, but is there a UK swap group maybe?