The Hotel La Cordillera offers monthly rates of US$2,088–3,480, depending on the room and number of people.
Just up the road is Apart Hotel La Cordillera (tel. 504/516-0520, www.aparthotellacordillera.com [1], US$70 s, US$81 d, US$20 more for suites with full kitchens). Although not quite as elegant as its sister hotel, it is still very nice, and a good option for those who will be in town for a while. The hotel has a minimart on-site, as well as a swimming pool, and all rooms have TVs, air-conditioning, and wireless Internet. There is also a two-story, three-bed penthouse suite available for US$319 per night. Discounts for long-term stays can be negotiated with the manager.
While they don’t advertise monthly rates, the many suite-style hotels (such as Suites del Valle and Monteverde [2]) in town can be good options for longer stays, and discounts for stays of a week or longer can likely be negotiated.
Links:
[1] http://www.aparthotellacordillera.com
[2] http://www.moon.com/destinations/honduras/central-honduras/san-pedro-sula/accommodations/us50-100