No, greenban, and it really isn't that sophisticated per se, but rather just a bit more thorough. In theory, you need to put in a real interest rate, an expected rate of general inflation, a separate rate of inflation in maintenance fees, a separate rate of inflation in rack room rates for competing Disney rooms, a rate for competing rooms at other Orlando hotels, a rate of interest on risk free savings, a rate of interest of taxable investments, expected income tax rates and changes in income tax laws AND DO THIS FOR EVERY YEAR TILL THE END OF THE CONTRACT!!! And, because this is correctly analyzed as a prepaid expense rather than an investment, per se, you have to use a declining balance approach to any alternative sum to put aside as the amount you prepaid into DVC (i.e., both scenarios must have you taking vacations at the same rate and time of year, otherwise you are not comparing apples to apples).
In actuality, unless you make drastic assumptions about the parameters, the quick and dirty method works pretty good. Generally, the effects of inflation are for the most part going to cancel out on both sides of the equation in this particular type of calculation, so ignoring inflation is generally OK. Second, the rates of return on investments that people cite are not appropriate because they don't take liquidity or transactions costs in account, nor do they account for the erosion of principal that occurs with a prepaid expense. Third, it is true that there is a time value of money apart from inflation, however, there is also a financial and psychological value to predictable expenses that must be given a role in the equation if you consider the time value of money. Unlike most time value of money problems, it is not simply a question of buying now versus later, but a question of buying now and fixing the price of services you buy till the end of the contract. This needs to be accounted for. For someone that is buying DVC, it is not inappropriate to assume that the value of the fixed price is equal to the real time value of money (that is the value outside of inflation factors), thus the time value consideration can be discounted away. This is all a bit esoteric way of saying that dividing your total cost of points (add the financing charges if you want) by the number of years remaining in the contract is a reasonable way of figuring what the points COST you upfront, and then adding the current maintenance costs is a reasonable way of figuring the annual cost since anything you buy with the points will be inflating at the same or similar rate to the maintenance costs (in the OP's question, the points for DL resort hotels can be assumed to go up at at least the same rate as the inflation in maintenance costs so valuing the points in constant dollars using today's maintenance fees is just fine and actually highlights how the costs of exchanges will likely continue to increase). The comparison for DVC resorts would be a comparison of the calculated cost of the points reservation (which will remain fairly constant in REAL terms) with the nominal cost of alternative accomodations (either cash at a DVC resort, or cash at a non-DVC resort).
And, I have seen the basis for the profit subject to intrerpretation, too. 
