I happened to stay at Road Lodge, the only hotel at Cape Town Intl. Airport. It was extremely cheap (about USD 25), clean, comfortable and functional. The room had a double bed, a large armchair, a desk, and a small television. The bathroom had only a shower (no bath); the water pressure and heating was fine. Breakfast was about USD 3. This hotel is apparently part of a chain, consisting of various brands, called City Lodge Hotels Group. It can be found on the Internet at:

http://www.citylodge.co.za/

and, apparently for lower rates, at:

http://www.stayandgo.com