Of course it all depends on LOCATION.In the finer neighborhoods, 1 br. apartments are rare, but should go for between $7500 to as much as $17,000(pesos a month-$US 1000).For instance, furnished apts. in NACO 2000 apartment building in the fashionable Naco area would be $US 1000.00.
The oriental zone and ghetto neighborhoods would be lower($2500-4500), but not safe for foreigners. Most foreign people stay within the limits of Piantini,Bella Vista, Evaristo Morales,Los Cacicazgos and Naco and Urbanizacion Fernandez. Mirador Norte and Sur are also acceptable and lower in price than the above, but not as attractive.
Other optional cheaper neighborhoods, but reasonably safe and clean are Ensanche Quisqueya, El Millon, Los Prados. Las Praderas is also within this category but slightly more expensive. Many of the so-called Dominican Yorks live in these neighborhoods.
Remax and Coldwell Banker are locally established and have plenty of listings in local newspapers. I found few listings in Internet.
If you wish to see the quality of the neighborhoods, just look at the cars in the driveways and parked in the streets, visit the area both in the day and night to see the difference, look at the way people dress and if there are Colmados(grocery stores),betting parlors, clubs, small stores and beauty parlors around, stay away from it! Too many people in the streets is a bad sign. Likewise street vendors, fruit vendors and the like. That means, dirty streets, rats, roaches and bad odors.