If you mean "Solo a RD$10" on the corner of 12 de Julio and 16 Agosto, yes, it is still open. But nothing there is cheaper than it ought to be. I have seen better prices in Margarita or among the "ofertas" in La Sirena.
It does have its uses. Friends went their to equip the apartment they had rented for six weeks. They could do it all in one place there and didn't mind shoddy stuff as it was only for six weeks, after which to be given to charity.
Needless to say, not much is priced at RD$10. First time I ever went there they were unloading cheap "home entertainment systems" priced around RD$15,000.