Try Santiago ! !
I've lived in POP for 10 years, & bought a lot of furniture.
* Overview: furniture, appliances, & almost everything else is more expensive in POP & Sosua; mainly because there are so many foreigners @ who have $ & are willing to pay more, usually much more, out of ignorance or for convenience.
* Solution: shop in Santiago [or Santo Domingo, even better]; generally furniture prices are @ 60% of what the POP prices are, in my opinion.
* Also, have a Dominican female go into the store 1st; have her try to establish the price, before the store learns of your white skin. Most [ie nearly all] DR funriture stores I have seen have no posted prices; a few do. Make an adventure out of this! There are also wood working shops that hand make furniture to your specifications; some of their prices are cheaper than the retail stores. Good hunting!