We are DVC members - we go several times a year but don't have the AP. What I"m about to say is certainly applicable to "once a year" families.
With DVC, it's a marathon, not a sprint. For example, if you buy into DVC (seriously look at the going rate on the secondary market and evaluate it against the specials offered by Disney), and if you buy a 10 day non expiration ticket with the 5 "extra" events through one of the discount sellers, say Maple Leaf or Undercover, then you CAN get a better deal over the long run and - this is a big and - you are locking in your fixed cost over the long run. Your room costs (i.e. point value) are locked in. Your ticket prices are now locked in - until they run out. And you can go to Disney, lounging in a sprawling 1 or 2 bedroom with a kitchen, washer/dryer, fantastic pools, etc. etc. Once you go DVC, it's hard to go back to a "regular" room.
Yes, we are exempt from the "free dining" deals, but to purchase the dining plan for a family of 4, it's ranges in the $80 - $120 day range, including tip. Or, you can be eligible for the TIW discount card that pretty much gives you 20% off table service (about the cost of the tip.) There are other DVC discounts - pretty minor in my book, but they are there and certainly not worth the cost to buy into DVC in the first place. The reason to buy into DVC is to lock in your price to stay at more luxurious accommodations in the long run for a fraction of what it would cost on the market.
So - if you don't want to "commit" to Disney, DVC is not for you. If you really plan on mainly using your points to trade out to RCI, the
DCL or non-Disney properties, really DVC is not for you. If you are buying because you think you SHOULD and it's not really a passion, it's not for you. If you have to go through crazy financing, it's not for you.
I would say if you are seriously thinking about it, get on one of the email lists for the resellers - there are a couple, including Timeshare store. Get to know the market. Then, the next time you price out a week long vacation, just see how close it would be to buying, say, a 100 point contract. Then it really starts to show perspective... for 2 or 3 of those vacations, you could have points for 20+ years. You'll see what I mean.
HTH