If you WANT to give Disney extra money for stuff you might not use, that's your choice. The previous is an example of a guest who purchases a dining plan for the convenience, not for savings. For many, the prepayment is the important part. Disney loves these customers. Nothing wrong with it as long as they realize they're giving money to Disney when they leave credits behind.
Personally I can't see how leaving 50 snack credits and 12 meal credits unused is a "bargain" but the previous poster sees it that way. Some people value the idea that they can grab a snack whenever they feel like it without opening a wallet more than actually planning to grab the snacks.
For the OP it will depend on what they really want - they want all the meals they want to book covered by dining credits because they see that as more attractive than paying out of pocket for them, and they would have to upgrade to deluxe to achieve that. If the prepayment is what's really important to them, they will know that they don't have to use all the credits, order everything to which they are entitled, or finish the meals they order.
My perspective is slightly different:
Last year we stayed Club Level and got the regular dining plan. We used all of our credits - using "unused" snacks and a couple of CSs to bring home a bunch of mickey rice krispies treats for friends and family. But, we also paid extra to do Hoop Dee Doo and a couple more table service meals that we wanted (we were there for 7 nights.) This added about $400 to our meal costs. We did not like the CS meals we tried - too loud, too hectic. So this time, we're doing Deluxe dining. We'll be 3 adults (me, my husband, and my mother) and 3 kids (all under 9, but one still under 3 - so free.) The cost for 7 nights on Deluxe = $1805.65. HDDR and dinner at CRT alone will cost 458.43, so the value I need to get on our 17 remaining TS credits is 1347.22. I've chosen 17 TSs - not even the most expensive ones, and come up with an additional "cost" of $1832.96. So, by paying $1805.65 unfront, I'm getting 2291.39 in table service meals. And, we'll have 70 snack credits too!
I've priced out the average costs of the following restaurants, using the menus on allears:
*The "@" stands for "about."
Deluxe Dining Review:
(2TS)California Grill (@70/@25)
$260
Coral Reef - lunch (@40/8) (@40/8)
$132
50s Prime Time Café - (@30/7.50) (@35/7.50)
$105
Chef Mickeys - breakfast 35.99/12.99
$133.95
TuskerHouse - breakfast (A: 20.23/K: 11.71) lunch (25.55/13.84)
$84.11
Crystal Palace (Adults B/L/D: 19-21-29) (Kids B/L/D: 11-12-14)
$79
Biergarten - (Adults L/D: 20/33) (Kids L/D: 11/14)
$127
Akershus Norway Princesses - (Adults L/D: 30.99/35.99) (Kids L/D: 18.99/20.99)
$130.95
Park Fare - (Adults B/L/D: 23/40/?) (Kids B/L/D: 13/20)
$95
Rose & Crown (@28/7.50) (@32/7.50)
$111
Liberty Tree Tavern (@25/7.50)
$90
(2TS) Citricos (55/10)
$185
(2TS) Narcoossees (55/16)
$197
O'Hana breakfast (24.99/13.99)
$102.95
For me, the biggest benefit is paying ahead and just not thinking about the cost when we're there! Sure, we'll pay the tips as we go (20% - which we'd be paying anyway, since we don't like CS), and for our beer and wine, but that's easy! For us, the dining plan makes for a very relaxing, easy-breezy vacation!
-Tricia