Amazon UK is running a buy one get one free Disney promotion from March 2, 2015 through April 12,2015. It is split into three separate "DVD", "Blu-ray", and "Blu-ray 3D" categories.
Promo page accessible here:
http://www.amazon.co.uk/b/ref=s9_acss_bw_hsb_DVDhomep_s1_s?_encoding=UTF8&node=5874046031&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=merchandised-search-2&pf_rd_r=1PH0MJ1XEE1P4P2WZGNC&pf_rd_t=101&pf_rd_p=588446887&pf_rd_i=283926
I used it to pick up Frozen 3D and Beauty and the Beast 3D shipped to the US for £19.90 (around US$31).
Promo page accessible here:
http://www.amazon.co.uk/b/ref=s9_acss_bw_hsb_DVDhomep_s1_s?_encoding=UTF8&node=5874046031&pf_rd_m=A3P5ROKL5A1OLE&pf_rd_s=merchandised-search-2&pf_rd_r=1PH0MJ1XEE1P4P2WZGNC&pf_rd_t=101&pf_rd_p=588446887&pf_rd_i=283926
I used it to pick up Frozen 3D and Beauty and the Beast 3D shipped to the US for £19.90 (around US$31).