We get it, couples need their privacy. And we wouldn't really be comfortable with dorm beds, although if you're travelling alone and enjoy meeting new people, go for it by all means. What we're talking about are totally private two-star double accommodation rooms in a hostel-hotel. The A&O chain has outposts all over Europe and we couldn't recommend them enough (they did not sponsor our stay in any way). Rooms at A&O Hostel Aachen Hauptbahnhof cost around €60 per night, but we got two nights at just €49 thanks to online vouchers. Always do a Google search for hotel vouchers before booking directly on hotel or booking websites. The best part was that the hostel-hotel came with a guest kitchen equipped with everything you'd need for tea, coffee, and simple meals, including a kettle, stove, microwave oven, oil and salt, plates, cutlery, pots and pans, and a medium-sized refrigerator. It even had a table with seating for four. The only caveat is that you have to do your own dishes but we think that's only fair.