Menus are in German, but even I was able to work out how to switch the language to English easily enough. I can't comment on the accuracy of the German dubbing etc., but the rest seems to have been done very well so hopefully that was too.
Bottom line - if you can play R2 DVDs and don't mind American Werewolf levels of nudity and violence this is a very good buy, a quirky and often very funny movie, and well worth a look at £2.
http://thatsentertainment.co.uk then enter "Bloody marie" into search and scroll down to DVDs. There's no box picture, but it's the right one. Don't know if they sell/ship outside the UK.
later - More about it here
http://www.imdb.com/title/tt0104511/faq?ref_=tt_faq_sm
following their links to comparison of the different versions, it looks like the biggest difference is a scene in which one of the vampires is burned "alive," which is considerably longer in the German DVD.
I've decided to sell my region 1 copy on eBay
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=131107043756
Starting at 99p as usual.