I can't see why DVC/WDW would want to prevent people from buying small resales. In fact, I think WDW would welcome it - here's why:
1 -- We purchased a 100 pt contract mid 2004 because that was all we could afford. Result: DVC got a new member, when they otherwise would not have.
2 --- We have been able to use that contract very creatively and re-visit WDW many times. Result: We've spent more money in the gift shops and on tickets because we had the accomodations paid for.
3 --- This year, we purchased an annual pass (which we wouldn't have done other wise) and are planning to return again this year with it. Result: Additional revenue for WDW in the 4th quarter of 2006.
4 --- We're going again in May wih my parens: Result: WDW is also getting more revenue from us because of an extra Dining Plan purchase (that includes 2 more people on this next trip than who usually comes with us.).
5 --- We purchased a small AKV add-on, now that we can afford more points. Result: More revenue to DVC 1st quarter 2007.
Another point - let's say someone sold their 2 small contracts at 100 points each to two different people. That means a net gain of 1 DVC member. Those new members probably will use their points to stay in a Studio, where the past member stayed in a 1 bedroom. This means an additional week of revenue for WDW because a whole extra family is using the DVC membership.
Any more members they can get to actively visit WDW means more money for WDW as a whole. Whether or not you are staying in a Studio or Grand Villa, food, souveniers, and tickets all cost the same each day for each person no matter in what accomodations they are staying.