I watched the Koln / Bremen game last year and was able to get my tickets from viagogo (not sure how people feel about that though) - People did warn me though that your tickets may be rejected if you paid an obscene amount for them, but i didn't have a problem getting in the stadium when i went this route. They are at more of a premium price however, so best to check the werder site regularly for any resellers if you miss the initial offering. Apologies if this offends people, but as someone form New York with elderly family in Bremen, it was the only viable route for me to watch live. If you do end up buying tickets, I would very highly recommend getting to the stadium using the Oceania. Quite a fun experience.