Here's a thought. How about book Swan/Dolphin and then do one of WDW's special New Year's Eve offerings or even see if you could book a specialty fireworks cruise that evening from an EP or MK resort? (Here is a link for specialty cruises if you are interested:
http://disneyworld.disney.go.com/tours-and-experiences/specialty-cruises/
I'm not sure how many people are in your family, but it's possible Swan/Dolphin plus one of the special events or cruises will come in less or about the same as Poly and it might be more special than standing on a crowded beach at Poly?
Here is some info on some NYE offerings at WDW (from all ears.net):
Walt Disney World New Year's Eve festivities for this December 31:
At Epcot, DJs will be stationed at select pavilions throughout the evening. "IllumiNations: Reflections of Earth" will salute the new year at 7 p.m. and 11:42 p.m. A buffet dining experience inspired by Disney's classic animated films Fantasia and Fantasia 2000 will take place at World ShowPlace, with reservations available from 4:30 p.m. - 10:30 p.m. Priced at $68.67 for adults and $44.37 for children. Park admission is required.
At Disney's Hollywood Studios, the Mulch, Sweat, and Shears New Year's Eve Spectacular will take place on a specially built stage in front of the Sorcerer Hat icon. The four concert sets will feature pyrotechnics and special effects and lead up to ringing in the New Year with Mulch, Sweat, and Shears playing live accompaniment to a full-scale fireworks spectacular.
At DisneyQuest, located at Downtown Disney, there will be a family-friendly cyber celebration from 8 p.m. -1 a.m. including a DJ Dance Party, character meet and greets, plus unlimited access to games and DisneyQuest attractions. There will be a confetti drop and festive party favors as the clock strikes midnight. Partygoers also will get a coupon for a quick service entree, side and drink. Tickets go on sale soon at 407-934-7639.
At Cirque du Soleil, located at Downtown Disney, all guests attending the December 31 performances will receive a limited-edition Walt Disney World/Cirque trading pin. Shows are at 6 and 9 p.m. For pricing contact 407-WDW-SEAT .
Registered guests at select Disney resort hotels will be treated to music and entertainment.
At Narcoossee's restaurant (Disney's Grand Floridian Resort & Spa), for instance, there will be a four-course dining experience for $161.85 for adults and $77.19 for children, plus DJ, balloon artist and special fireworks viewing.
Atlantic Dance Hall at Disney's Boardwalk Resort offers a special-ticket New Year's Eve party from 8 p.m.-2 a.m. with a video DJ and limited viewing of Epcot's fireworks.
For specific information about other holiday dining offerings at Disney resort hotels on December 31, call 407-WDW-DINE.