I find myself agreeing with Freyja. I too would have a hard time paying $500 for a hotel room. I would go up to $350 for a high-end resort (which is what we're doing in Kauai, Hawaii in 2 days), but I draw the line there.
I have visited the DLH when my in-laws were staying there, and we have stayed at the PP. My DH and I didn't find any extra magic or get any extraordinary feedback from our DDs. The DDs were just interested in going to the parks every day. We barely spent time in the room. From that point on, my DH and I always opt to stay off-site when we go to DL/CA. Our upcoming visit on March 16-19 (on our way home from Hawaii), we'll be staying at the Doubletree Anaheim for $52/night, bought from Priceline.com. With the $$$ we saved, we'll be spending it on shopping at those fabulous Premium Outlets, Target stores, and all those other stores we don't have in B.C., Canada, as well as buying souvenirs.
My exception is WDW. There, we always stay on-site, because it makes all the difference. But even there, I've never spent more than $150/night (and we've stayed at the Dolphin, POFQ, and POR).
If you want to and can cancel your reservation, then maybe you should. Is there a penalty? Maybe in order to save money, you'd have to pay a small penalty. I find that TAs in Vancouver sometimes ups the hotel prices. Isn't that how they make their money??? Once we were looking to stay at the J.W. Marriott Cancun. TAs were quoting $450-$632 for a room...but I got it on Priceline for $105 for the same dates. Go figure.
Good luck. I hope you get this resolved and just get to enjoy your trip.