As for "other" costs, it depends -- do you spend a lot on vacations now? Do you visit WDW frequently? Or would DVC be a facilitator to increase your vacation level? If the former applies, you will probably fare well with DVC -- you already know how pricey the "world" can be, and DVC will simply be a way of setting aside your dollars in a different way to finance that.
But if the latter is more correct (DVC will mean more trips, or longer trips, to WDW, than you ever took before), that's a matter to definitely consider. WHen we joined, we were a fam of 4 (studio-simple and kids were young enough to not need tickets, even!) We bought thinking we would visit 1x per year, for about 6 days. Now we're a fam of 5. We always bring along family (why not... we already have a 2 br, what's an extra grandparent or two?) We buy a fair amount of groceries, and usually treat our guests to whatever dining we do in the villa. Our oldest is nearing adult fare ticket prices (yikes); all now need some sort of ticket. Gas is expensive, and airfare evenmoreso, so we drive, but it requires a hotel room. So after trying a few different scenarios, we elected to do 1 big trip evey other year. It saves at least on transportation costs by 50%. I have done the math, and for our moderate spending (we eat out some, eat in some), it is roughly 4 to 5 K for a 12 day WDW trip. So that's now a cost we budget in a special WDW savings account, so that we can spend without fear or guilt on vacation! The 18-24 mos inbetween trips helps us build us that reservoir.
I agree with a prior poster that 9.75 is not very nice, especially with today's rates. THat's why our DVC is all paid off. I see WDW being probably as "greedy" as any other business whose goal is to turn a profit. It is, after all, a business, and that can be easy to forget amidst the heart-grabbing adds geared towards magic, importance of family, togetherness, and memory-making. While perks would be nice, as long as DVC continues to sell with whatever package they are offering, they are in the catbird seat and don't have to offer the members anything. They did, however, get a taste of just how far they could push their loyal republic when they tried that change to dining reservation windows earlier this year -- the DVC / AP-holder peasants revolted and they backed off from THAT plan.