Good matresses are expensive, name brands like sealey and whatever other good ones run 500$ US + for queen and 800$ US + for king. Cheap ones are.. cheaper, but my mother once said a good mattress is a very good investment.
The locally made ones are poor quality and the costs of shipping and import tax makes US name brands very pricey. Dominican foam pads seem to break down quickly into crumbles.
a cheap dominican mattress will start well below 10k pesos, an expensive memory foam will run over 100k. there is something for everyone.
and i don't think beds are that expensive if you live modern designer furniture your jaw will drop at the prices asked for that in DR. even an armchair can send you back few thousand dollars
my advice when it comes to bed itself is to have it made. we had one made by a dominican carpenter. very sleek, simple and modern platform bed from solid oak. with two small bedside tables, also from oak. 1k dollars. the cheapest decently looking set sold in POP was over 2k dollars.
this subject - mattress - comes up every so often on this site. the last thread i read on this said that it would be better to buy the mattress in the US and pay the $100-$150 shipping cost. at the end of the day you know you have a good quality mattress which not only is going to last you 10-15 years but it will also improve your health.
One option to consider if they work for you would be a Select Comfort mattress. They are essentially an air mattress that you can adjust for your own comfort. They normally have independently adjustable his and her sides. I have been using one for 15 years and because you are supported by air it is in the same shape as when I purchased it. No springs or padding to deform over time. Because it is not big and bulky to ship, it might even be worth importing one yourself.
Ad today in Diario Libre talks about Sleep Center at the El Pino Commercial Center in Los Jardines, on Ave Texas (in back of the Politecnico Femenino)....on the corner of the place...Big sign out front.