Yeah, that's how much it would've cost us had we had guests staying off of the resort we are staying at(Melia Caribe). Most AI resorts will charge a fee for a pass. I would send an email to the WC's at the PPR to find out how much a day/night pass would be to have outside guests come to your wedding.
Have you thought about the RUI's in Punta Cana?? There are five resorts on one property all at different price points/star ratings but are able to stay and play at them all (except for the RIU Palace). I think that holds true with the Iberostar's as well. If the price is what the guests are concerned about...this may be another option for you.