Lots of info here but I don't suppose you can get it "cheap" anywhere:
http://www.ambarazul.com/
I have seen blue amber in Latvia, along with other unusual colors. It is real amber but it has been processed to give it the colors. I have no doubt that if you found anyone offering blue amber in the DR at an affordable price it would be the same situation. Still very attractive, and still amber, but no great resale value unless you found another mug to take it off your hands. Natural blue amber is rare and expensive, especially now there is plenty of spending money in China and the Middle East.