Well, you asked me for my opinion on your inputs and assumptions, and I gave it. I don't know what others had said to you
Of course; I was just crying out to the universe.
If I read correctly, you seem to think dues had been rising faster than inflation but eventually should come down to track inflation. I disagree. Disney makes a profit on dues and it is part of the return calculation for Disney as a developer. I think dues will perpetually increase at a faster rate than inflation.
I think I get what you're saying, but that really can't be literally true. No price can increase perpetually faster than inflation. It's the magic of compounding; eventually it becomes larger than the entire money supply. Before that happens, it gets larger than anyone can pay. The prices of hotel rooms (like any other prices) must go up with inflation, though they can go up at a higher rate for a long, long time. So I'm happy to stipulate that the dues can go up faster than inflation for longer than we care about, or longer than the life of the DVC contract, but not forever.
The key is whether the growth in the spread (currently at $9.16 using the most inefficient 1BR example) tracks inflation.
Right. And it hasn't thus far for the life of DVC, which is more than 20 years, so we do have a decent history on this. I think it will in the very long run (see above), but it hasn't so far, so assuming that it will is fine for an off-the-cuff quick check, but not completely defensible.
The way I would look at this is to compare the IRR of DVC to the IRR of long term bond return which is the 4.5% rate that you used.
Sure. Perfectly valid, as long as you calculate the IRR accounting for reasonable assumptions about the long-term growth of the "payments", i.e. the discounts from room rates. For DVC, the discounts are big enough that you can be a little slapdash and it still comes out clearly a good deal. But for some cases, it's going to be closer and it'll be worth actually doing a more rigorous analysis.
If your argument is that if the quick analysis shows that it's clearly a good deal then the more rigorous analysis is a waste of time, then you got me. You're right. I just like working out the analysis.
Why don't you think it's the most intuitive way? Comparing the real IRR of different assets is the most pure apples to apples comparison in my opinion.
I think a lot of people are not super familiar with rates of return and what is a reasonable rate for comparison purposes. You meet people who think that it's perfectly reasonable to be able to expect to make 15% per year, every year. That's fine if they're Warren Buffett, but...they're not.
With NPV, you're comparing quantities that people are familiar with: dollars. I'm asking "Is it worth spending $X to get something with a NPV of $Y?" You can also fiddle with the numbers and answer questions like "How far do my assumptions about long-term cost growth or insurance have to be off before this is no longer a good buy?"
And with amortization, you're answering a question that people often have, which is "if I pay this much today for something I will use over X years, how much per year is it costing me?" Though for reasons outlined earlier, I find amortization to be somewhat problematic, because the traditional methods assume a constant nominal payment. Real situations (like DVC) do not have constant payments. And inflation means that constant nominal payments are actually declining real payments.
But don't get me wrong - IRR is yet another way to go, and if it's what you're most comfortable with, that's what's important.