I tend to have a different outlook on DVC than most, but my analysis made sense for me so that's why I became a member. I will explain my thinking because it may encourage you to think "outside the mouse" so to speak.
I think anyone gets bored with a lifetime of vacations to the same or similar locations. That's why my view of the value of a timeshare has to do with the options it provides me to go elsewhere. Everything you indicated involves staying in the Disney system, and while I concur with everyone else that that provides you with the most bang for your buck, I think determining if DVC makes sense for you strictly on that criteria would result in many people not finding DVC to be the value that I truly believe it is. The value I see in DVC is that my investment is fixed and the value I receive becomes variable over time as accomodation costs increase. Since hotel prices tend to rise 8-12% annually, over the course of a DVC contract you can get quite a value 20 years down the road when you are using them for an RCI trade into a hot market and still spending the same points for a week away in Aspen for example. In the 10 years I have been a member I have already seen that value occur. Let me explain my entire process.
My initial valuation involved a lot of math, but to do it right, I think it needs to, and I knew I'd be using the number for 40 years, so I figured a little hard match up front with a 40 year payoff was worth it. Take your initial investment for your points and if you are financing obviously include all the interest in the loan. Take your maintenance costs and assume a 2-3% (you pick the level depending on how conservative you want to be) increase per year over the course of the contract and multiply by your points each year (so for me we bought 200 points, so over 40 years I get 8,000 points) and add all that together to get that number. Those are your true lifetime costs of DVC. Now you take that entire total and divide it my your lifetime points to get a cost per point. In my case it is $5.64. That is the magic number I use now for the rest of my life.
So if I want to book a
Disney cruise on the Disney Magic in 2016, for a level 5 stateroom in the 1st quarter it will cost me 90 points per person, or 180 points is my wife and I want to go. I take those 180 points and multiply by $5.64 and get $1,015.20. If I can purchase that room for less than that, I am better off using cash. If it is more, than the points just saved me the difference. When I took my family on a trip to Williamsburg, VA a couple years ago, it required 260 points for a two bedroom for a week, or (punch into my calculator and watch the numbers whirr), $1,466.40. The going rate for rooms in hotels that we would stay in as an alternative at that time was $149/night at the best discount I could find and I would need two of them to accommodate 6 of us. Again, using math, I got $2,086 or $1,043 * 2, so having DVC saved me over $500 on that trip alone AND let my family stay together instead of in two hotel rooms and we had a living room and a balcony and access to a very nice pool on top of it. Is DVC worth the investment? It becomes very, very clear for us that yes it absolutely is. As hotel prices keep going up and my kids age and eventually it is just my wife and I and we go to Europe or on African safaris and I an using my $5.64 points to book a safari that is costing me a little over $3,000 per person when everyone else is paying $7,000 in cash, I'll just be smiling away.
Now if you are OK using Motel 6 or Johnny's Sugar Shack for $29/night DVC does not make a good investment, because even 30 years from now those places will be under $100/night and it will be less expensive, but if you prefer moderate to high level accomodations to feel pampered when you are on vacation then I encourage you to spend a little time on the math, find your number and use that to make your decision, because you will be surprised how many times you can save hundreds or thousands of dollars when staying outside of Disney as you will after the kids are gone. You are buying vacations for the next several decades at today's prices. Sure the points may go up to trade out as they are not locked in, and I have never found the trade to the specific hotels cost effective but if you do the RCI trips to some great places in Europe or the US, it is not just Disney vacations you are buying, but the world.
Hope that helped.