Juliet - St. Croix St. Croix Liveaboard Diving
The Juliet LOB looks like a very good option. The trips are $1690 per person for a standard cabin and covers and $1890 for a cabin with an ensuite bathroom, and the price covers:
Included: Three buffet-style hot meals per day, plus snacks and hors d’oeuvres, non-alcoholic and alcoholic beverages, tanks, weights, weight belts, fishing and spearfishing equipment
Additional: Port Fee, Air transportation, Ground Transfers, Industry Suggested Gratuity of 10-15%, Nitrox, Specialties and Certifications, Rental Gear
I think that port fee is only for the Bahamas but I am not sure, and the Nitrox is an extra $100 if desired. So with airfare and transfers it will likely exceed $2000 pp but it will be close - nice!
I was trying to think of a liveaboard option but I could only come up with Blackbeards, which would definitely be under budget, but sometimes you get what you pay for!