At the SJU airport hotel I usually paid $142/night with taxes, When I had my BVI driver's license it was $115/night (Caribbean local's discount).
I found they don't last minute discount as they specialize in stuck people. If you go to an off airport hotel, that adds a lot of time and no free hotel shuttles.

Been a while since I have been at SJU, but this hotel used to be the the most confusing place to find.