Excellent advice.Do NOT do it. Once you declare it on leaving the US you will have nothing but problems. One of them is you will be flagged in US Customs permanently whenever you arrive in the US.............Take a check and get it cashed in the DR..............Not to mention your arrival in the DR will not be very pleasant for sure.................
I was going to say the exact same thing.
DO NOT ATTEMPT to carry that much cash thru an airport regardless of what the law says.