I'll try and describe it as best I can. We purchased 200 points. We get additional 200 points every March 1st as our "use year" is march. This point is important once you figure out what time of year you like to visit.
You use your points just as you would money. Example.. one night (a Sunday, Monday, Tuesday, Wednesday, or Thursday) in a studio (which is the same as a hotel room but includes a fridge, toaster, microwave) in November costs 8 points at Old Key West. Therefore I have 192 points left.
If you wanted a one bedroom or two bedroom naturally it is more points. The newer resorts are also more points. Beach Club for the same as above is 11 points. So, you have to figure out how many people you have in your family and what accommodations you want. High season times cost more points than lower season's. Then determine how long you want your vacation to be each year. That's how many points you need to buy. However, if you only go every other year you need less points because you can "bank" this years points into next year. This is where "use year" becomes important. If you want to bank all your points then you have to do this 9 months ahead of time.
DVC works really well if there are a few times a year that you can take a vacation. A school teacher who is very limited to when they can take their holidays (ie only during the high seasons) will have to pay more points and will have to book their rooms as soon as they are able.
You can book a holiday at your home resort 11 months before the end of your vacation. ie if your holiday is November 1 - 10th, then you can book at your home resort on December 10th of the year before. If you are staying at a non home resort you can't book until 7 months out. That is why some people prefer resale. They aren't flexibile in their holiday time and they want to stay at a specific resort so they buy there.
Currently, Saratoga is good for another 49 years. The other resorts are much less time. I want to say 32 to 37 years but don't quote me. It is real estate so you can resell it or will it to your children, but hopefully live right to the end of your contract.
You can also use your points at other Disney hotels,
Disney cruise lines and can exchange your points to many, many hotels all over the world.
They are only good for the hotels. It is timeshare in that you actually own a piece of a room at whichever resort is your home resort. We also get a $100 discount on Annual passes this year. There are other perks such as percentage discounts at restaurants, stores etc.
Like I said before we pay a monthly charge that our finances can handle and it's nice to go on vacation and NOT have the huge hotel bill at the end.
I almost forgot. You also have to pay maintenance fees once a year as well. It ranges between $3.50-$5.00/point. (again I'm going from my memory here). Just like a condo the maintenance fees are lowest at the newest resort
I hope this clears up your questions instead of making it more confusing.
forgot to add that you must purchase a minimum of 150 points to begin with.