Hi, Brian!
I am a die-hard believer in the Disney Dining Plan. IF you
know that you're going to eat in the parks, then the various Dining Plans are absolutely worth it. We always travel with the
Disney Dining Plan because it enables us to sit down and relax for an hour or so a day. Moreover, we try to maximize that dining dollar by ordering the most expensive item that we like on each menu. It feels like a splurge, but it doesn't cost you anything extra! :-) )
To best compare what you'd spend eating around the parks OFF the Dining Plan, to what the costs will be ON the Dining Plan, you can check out
unofficial menus, including prices, at allearsnet.com. This is NOT a Disney site, but I often consult it, since the variety of offerings and costs remain somewhat the same. I suggest that you add up what you'd expect to spend each day in the parks or resort and then determine if the Dining Plan will save you money. That might be all you need to decide if this plan is right for you.
Now, regarding time constraints, you can opt for the Quick-Service Dining Plan, and pay out-of-pocket for the one character meal. Those Quick-Service restaurants allow you to pop in whenever you're ready to eat; no reservations required. However, if you really want one character dinner, you really need to book that as soon as possible. The most popular of them all book up quickly, especially due to the popularity of the Dining Plans, so the sooner you can tie yourself to that one reservation, the better. Check out
the list of Character Dining options at Walt Disney World for more information.
Send me any additional questions you may have regarding your upcoming vacation! I love to help!