Marriott Westchester: As a Gold checking in this weekend, I given coupons for Continental Breakfast for two ($13.95 list price pp) and told there was a $5 up charge to the full buffet.
I was also given a $10 Platinum F&B coupon which covered our up charge for one of our two nights, but I believe that was because I had made nice with the woman who checked us in, and not because of standard hotel policy.
The buffet was exceedingly average.