Hi Keith,
DVC current is offered in two options. Saratoga is the only one offered for sale by Disney at the moment and it's expiry date is 2054. There are resales of the original DVC offering which give you a choice of OKW, BWV,BCV and VWL on site. Away from Orlando there are DVC resorts at Hilton Head (South Carolina) and Vero Beach on the Atlantic coast of Florida (about half way between Daytona and Miami) The "original" DVC resorts expire in 2042. A resale should give you a few more points for the same amount invested as it has less years to run.
For $15k I would expect he has somewhere in the region of 160-180 points, Disney offer you the option of some dicounts if you rent them back some/all of your first years points. Personally I don't think the discounts are a great deal, unless you know for certain you won't be able to plan a trip for that year.
How many nights is another difficult question to give a specific answer to, it really depends on size of room/unit, how,when and where you would use your DVC points. One of the beauties of DVC is the flexability it offers the members there are so many different ways you can use the points it's almost too many to mention. I'll try to give you some brief examples at the end, after I've answer some of the other points you've raised.
Size of Room/Unit DVC comes in 4 basic sizes of unit they are;
A Studio, this is basically a regular hotel room size and sleep 4 people plus a child under 3. OKW has two queen sized (proper)beds, the other resorts I believe have one queen bed and a sofabed (not 100% sure on VWL set up)
A one bedroom unit. This has a separate master bedroom with a kingsize bed (and a TV) with an ensuite jacuzzi, a separate shower room/toilet, a living dining area (A double sized sofabed, a TV) and a fully equiped kitchen and a balcony. In terms of room area I would guess the one bed units are between 2.25 and 3 times the size of a "regular" hotel room. These units also sleep 4 people plus a child under 3.
A 2 bedroom unit is basically a studio and a one bedroom connected together. In some cases they are "lock offs" so the two parts can be used independantly. In these cases both parts have a separate entrance and the connecting doors can be locked by either party. In other cases they are termed a "dedicated unit" which means there is just one entrance to the unit and the door that leads to the second bedroom/studio area is a "regular" door as opposed to having a set up like you would see in a hotel room that has a connecting door to the room next to it. These units have an occupancy of 8 people plus a child under 3
The final unit size is a "grand villa", these are three bedroom units. The master bedroom is similar to the one bedroom it has then 2 bedrooms each with 2 queens or double beds (not sure which) and a pull out sofa in the living room. A large living/dining area with open fully equiped kitchen. At OKW and Vero I would guestimate the size of the unit at about that of a decent 3 bedroom semi, in the other developments they scaled back a little on unit size and I would estimate a reasonable sized 3 bedroom apartment. The units sleep ( I think ) 12 plus one child under the age of 3.
How and When you use the units Friday and Saturday nights are much more expensive than Sunday to Thursday nights (about 2.5 times the price) If you can cut down on weekend usage you can save a lot of points. DVC pretty much has four "point price" bandings throught the year. Xmas and Easter are the most expensive times, the other three "seasons" reflect their popularity. If you want to check out exact dates and unit costs here is a link to a DVC points calculator
http://www.wdwinfo.com/resort/dvcpoint.cfm .
Where you use your points THe different DVC units all have a slightly different points cost. OKW is the cheapest resort. This doesn't reflect any shortcomings of the resort ( it's a fine resort) , but more the fact it was Disney's first DVC resort and once they had set up the cost schedule for the resort, they couldn't change it. After the success of (OKW) DVC and they saw the actuality of the units, I think Disney realised they didn't need to produce the units on quite such a grand scale ( the following DVC units are all smaller than OKW) and that they could charge more points per unit as well. Basically Disney "fine tuned" the system so they could charge more money, for smaller units thereby increasing their profitability without appearing to be too greedy.
OK given that information I'll give you some examples of what 170 points for example could be used for.
Using the cheapest resort (OKW),staying in the smallest unit ( a studio) avoiding Fridays and Saturday nights (checking out and staying somewhere else) and at the cheapest time of year, you could book 21 nights accommodation (8 points a night) (weekends would be 20 a night)
A studio at OKW in "Premium" season (most expensive) you could get 11 nights if you avoided weekends (15 points a night, weekends would be 36 points a night).
For a one bedroom, OKW, low season and no weekends you'd get 11 nights. (16 a night, weekends are 40 a night)
a one bed OKW, Premium season is 30 points a night weekdays and 78 a night weekends
2 bed, OKW, low season 22 points a night weekdays, 54 at weekends
2 bed OKW premium is 41 points weekdays, 100 weekends
A grand Villa OKW, low season 36 a night weekdays, 88 at weekends
Grand Villa Premium 66 a night weekdays and 162 a night in Premium.
The Other resorts points costs are between 20-50% higher than OKW, depending on units/time of years etc.
Here's a link to the DVC information available on this site
http://www.wdwinfo.com/disney-vacation-club/index.html
