Accommodations are few, and expensive compared with those in other comparably sized cities; for the annual March rodeo, prices can skyrocket. The best value is Hostal Yaiman (Bueras 655, tel. 072/641773, US$18 pp with breakfast), but Hotel España (Av. San Martín 367, tel. 072/230141, fax 072/234196, US$28/41 s/d) is a good alternative with private bath and breakfast.
Midrange choices include modest Hotel Rancagua (Av. San Martín 85, tel. 072/232633, www.hotelrancagua.galeon.com [1], US$38/55 s/d) and Hotel Aguila Real (Av. Brasil 1045, tel. 072/222047, fax 072/223002, US$47/67 s/d). Hotel Turismo Santiago (Av. Brasil 1036, tel. 072/230860, US$83/113 s/d) is ostensibly a four-star facility.
Links:
[1] http://www.hotelrancagua.galeon.com