First off, I'm glad to hear that we're discussing and not arguing. It's sometimes kind of tough to tell when you're on a message board and not talking face to face.
Anyway, I agree and disagree with your analysis. I agree in that if you decide to pay full rack rate for a studio at Animal Kingdom, Jambo House, then you will break even pretty soon (it's actually year 5 once you account for interest paid and maintenance fees increasing at 2.5% annually).
But here's the problem I have with your analysis. Like Dean said above, unless you actually plan on staying at AK Jambo Studios and paying full rack rate, your comparison is not honest, it's more of a justification to purchase DVC. The numbers you quoted assumed a stay during Dream Season. Well right now there is a deal for 30% off rooms during that time. So that changes the numbers a bit.
So without pasting in a huge spreadsheet, let me sum up my analysis.
DVC Cost = cost of points, plus interest, plus maintenance fees
Outlay JH = full rack rate at Jambo that you quoted earlier
Rental JH = cost of renting points for the same stay at Jambo studio ($13pp)
Outlay SSR = cash cost of studio at SSR (your home resort) assuming 30% off
Rental SSR = cost of renting points for the same stay at SSR studio ($13pp)
Scenario #1 DVC vs. Full Rack Rate Jambo
Break even point is year 5. DVC costs $15,395. Cash costs $16,245
Scenario #2 DVC vs. renting points at Jambo
Break even point is year 17. DVC costs $22,779. Point rental costs $22,984
Scenario #3 DVC vs. 30% Discount rate at SSR
Break even point is year 11. DVC costs $18,814. Cash costs $19,519.
Scenario #4 DVC vs. renting points at SSR
Break even point is year 22. DVC costs $26,562. Cash costs $26,598.
So as you can see, there are many ways to analyze the "DVC or not DVC" decision and these are just a few of the possible outcomes. It seems that you chose the worst case scenario for booking cash and then compared it to buying DVC. If that works for you, great. I'm not trying to say that you made a bad decision or that you shouldn't have purchased DVC. But I do think that your analysis is more geared towards supporting your decision than it is taking a look at all the options to find the most cost effective one both now and in the future. In the end we are going to do what makes us happy, and I hope that your SSR purchase does just that. DVC is about more than just the numbers, and to a lot of people, that is worth any cost. Enjoy your purchase!