Lotusland Hotel: Nanning.
Dorm beds for about US$8 a night.
Nanning City Hostel: Min Zhu Da Dao (Min Zhu Ave), just behind Yang Guang 100 Apartments (Sunshine 100). Phone: (+86)152-7771-7217 (English), (+86)152-7800-0950 (Chinese). Email: nanningcityhostel@hotmail.com. Website: website here.
Guests can make use of the kitchen, while the hostel can sort you out with a Vietnamese visa. A single room with shared bathroom costs 80RNB per night.
Also check out YHA China for dorm beds and singles.