First off, congratulations on getting a way in, you'll love it. And be sure to go to the bathroom even if you don't have to use it.
Lunch is a buffet plus you order an main dish from the menu. Dinner is strictly from the menu, no buffet.
I'd double check with your friend, it may be $48 plus your meal. Usually a meal at Club 33 comes with park entrance, and the price quoted is a starting price. No break for annual pass holders either.
Can't help with the merchandise. When I was there, they were out of most items, so they just decided not to have anything for sale. But, I got my souvenirs in the bathroom. The paper towels are real fancy and have an embossed Club 33 logo on them. Plus your park ticket will have Club 33 printed on it with the date.