For whom likes more privacy here some options.

Villa Trallala (very modest, friendly and also affordable. 10 km on the motorway)
Marion Höppner, Albertus-Magnus-Straße 14, 57072 Siegen
Phone: +49 271-3134646 (telephone bookings preferably between 10am-10pm), villa-trallala.de

Richard-Martin-Haus (very nice and in a forrest, good price. 15 km normal street)
Tagungs- und Gästehaus, Siedlung 94, 57271 Hilchenbach
Phone: +49 2733-4215, Mobile: +49 151-42231140, Fax: +49 2733-7071, richard-martin-haus.de

Gasthof Schausten (modest and affordable, 5 km)
Eichener Str. 119, 57223 Kreuztal - Eichen
Phone: +49 2732-8384, gasthof-schausten.de

Gasthof Belz (very modest and affordable, 3 km)
Heesstr. 178, 57223 Kreuztal
Phone: +49 2732-1358, Mobile: +49 175-9833673

Gasthof Merje (8km)
Kredenbacher Str. 18, 57223 Kreuztal
Phone: +49 2732-2253, Fax: +49 2732-57526, merje.net

Hotel Restaurant Ongelsgrob (6km)
Buchener Straße 42, 57078 Siegen-Buchen
Phone: +49 271-8801020, Fax: +49 271-88 01 02-20, ongelsgrob.de

Hotel Zum Anker (very friendly, ca. 7km)
Hagener Str. 290, 57223 Kreuztal
Phone: +49 2732-89550, Fax: +49 2732-895533, hotel-zumanker.com

There is also a list of private pensions in the accommodation list Kreuztal. We don't know any of these though.