The Palms $50 "comp" in the Pocketbook of Values coupon package that comes with a one-year subscription to the Las Vegas Advisor (click here for the full list of coupons, worth thousands of dollars in savings) is a "matching coupon." This means that you get a 50% discount when you spend up to $100 on select experiences at the Palms.
In your example, if the cost of four buffets comes to $68, the coupon would be worth $34 (50% x $68). If there were six people in your party for a total tab of $102, you'd get the full $50 off. If you stay at the Palms in a room that costs $159 for the night, you'd also get the $50 discount.
Note that this coupon is good Sunday through Thursday only and you must be a Club Palms member. Also, the coupon can be used for charges in Gardunos, the Blue Agave, the Bistro Buffet, and the 24/7 coffee shop, the bars, the Palms Spa, the Palms store (for logo apparel only), and a hotel-room bill, along with admission to Rain or the Ghost Bar. The coupon isn't valid in the rest of the restaurants and clubs.
If you extract maximum value from this POV "master coupon," you'll save the entire cost of a hard-copy subscription to the Las Vegas Advisor. In other words, the $50 you save on this one coupon covers the entire cost of your membership when you opt to have the printed newsletter mailed to you (you'll profit by $13 if you opt for the online version). That's a deal that can't be beat.