Yes, it will be expensive. Ilumel (Santo Domingo and Punta Cana), Hach? (Santo Domingo and Santiago), Von (Santo Domingo) and several others come to mind.
Conforama (Santo Domingo Av. 27 de febrero and MegaCentro in the Zona Oriental) is a cheaper option for modern designs but the quality is not that good.
PM me if you would like contact details for a good furniture maker in SD who has done some good work for us at reasonable prices.