There's a dining plan calculator that I'm sure someone can link for you soon (I don't have time to find it right now), but in terms of price, I've seen a lot of people who claim that it pretty much works out close to being the same price. Of course, it's going to vary greatly based on where you eat and the price of the meals you would choose. The dining plan seems like it would make you eat more (for obvious reasons). Rather than having a light snack, you'd just use a meal credit because you have it. I'm simultaneously loving and hating the idea that I get the
free dining plan for my upcoming visit
Based on that fact that you want to be somewhat careful about how much you eat (don't most of us? lol), I'd say that you'd be better off paying out of pocket. You'll probably pay less and eat less - but that doesn't mean you won't have enough to eat (believe me, you can still eat well and still not spend as much as you would on the dining plan). Bring some snacks with you to the parks (granola bars, things like that) to tide you over between treats and meals. Also, there are some really great counter service places that you can hit up as an alternative to the more expensive table service or buffets. You'll eat less, and it's easier to avoid dessert when you're not on the dining plan. With the "automatic" desserts for all dining plan credits, it's hard to avoid them when they're
right there for no extra charge.
Yes, you do tip for table service on the dining plan (they show you what the cost of the meal would be and you tip based on that), so that's definitely another factor to consider with the price.