LAN is having a Business class sale from MIA - PUJ for $498.50. If you need to get to MIA you can use Avios which is really inexpensive (15,000 from NYC). Tickets are booked into I class which can earn you 125% of miles flown if you credit it to your BA account, so your Avios account should be somewhat replenished.
Dates that worked for me are 11/11 - 11/18. For those dates an economy ticket is going for $383 so it is a nice deal.
The flight is only a little over 2 hours but it will be comfortable on board. LAN's business class seats on their 767's recline into fully flat beds.
http://www.lan.com/en_un/info_viajes/clases_servicio/index_premium_business.html
