Casey Anthony -- FINALLY Talking ... for a Price (VIDEO)

Casey Anthony is ready to sing like a canary -- a well paid one -- because TMZ got video of the acquitted alleged child killer touching down in NYC, and she's about to do a big interview.

Casey flew into NYC late Thursday. Our photog had a strong feeling it was Casey, even though she denied it. But we figured out she's the real deal.

The white-haired gent by her side is a PR guy who was negotiating an interview with the networks right after her 2011 acquittal. As we reported, Casey wanted cash and some networks were wheeling and dealing, but all got cold feet in the end.