Montel, i tried a while back have you had a go on ebay? Depending on how many your looking to get rid of you could do what i did.
I bunched them together in bundles of 15-18, postage on a pack that big is around £7.50 royal mail. It all depends on how much you want for them, i sold about 120 dvds this way on ebay advertised as dvd bundles.
Another thing you could try is play.com's playtrade section or even amazon, this is a slow process tho as your dependant on someone wanting that particular film etc.
Or try
http://www.cex.co.uk/sell/ and see if there is one close to you, again they dont pay much (they offer more ££ fortrade) but good for trading etc if you play console games, ive even swapped a few dvd's for a blu before now.
Hope any of that is of help to you mate.