Re: Complete answer
I believe that was the Central Bank Exchange fee of 5% of US$4200 x 3 laptops = US$620 = about RD$10,600. I paid 5% in July 2000. I think the exchange fee has now been lowered to 1.5% and will eventually be eliminated.
There is also an additional and separate tax called ITBIS (Tax on the Transfer of Industrialized Goods and Services, aka, value added tax), calculated on the cost of the item plus insurance, shipping, and other import taxes, aka, CIF (cost-insurance-freight) + import taxes.
ITBIS, being calculated on an amount that includes import taxes, is sort of like a tax on a tax. ITBIS used to be 8% of the combined CIF and other import taxes.
These are above and beyond any import taxes. I have been unable to locate the current ITBIS, exchange commission, and other import tax rates. They seem to change so frequently that even the customs employees don't always have it correct or charge the official rates.
At this point, I can't be sure whether the exchange fee, ITBIS fee, and/or import duites apply to computers, let alone the current rates.