I don't know any shops but theres 2 websites that use the post, www.thatzdvd.com which uses a freepost address, you can sell for money or online credit because the site also sells 2nd hand dvRAB or for bulk sales try www.filmvault.co.uk which will collect the disc from you for no charge, you send them a list of disc and they will ring you with a value and send you a cheque when they receive ypur discs.
Ive used both and can recommend both. (thatzdvd for angel box set you'll get a round
