I attended a Borussia Dortmund match, and as the entire city basically sells out, I found the next best thing in Bochum. Priced extremely well, it was cheaper than a hostel for much nicer amenities. Trains leave from Dortmund to Bochum every 10 minutes or so, so took a train to Bochum Hbf, then the u-bahn to Reinsingstrasse. Total trip takes about 30-40 minutes depending on waiting time, but you exit a five minute walk from the hotel. Checked in with the automatic check in machine as reception only works in early morning and evening, but had no problems. Bathrooms and room were clean, unfortunately didn't try out the shower. Beds were comfy. Would be my first choice if I went back in the area