I Just bought a 50 point contract and it can certainly work. The idea right now is that it is enough points for a week in a studio every other year.
It allows you to try out membership without financing a big purchase. You can always add on points through Disney once you are a member in amounts as small as 25 points when you can afford to. Many smaller contracts allows you to sell in small increments later if you find you want or need to.
Small contracts go fast. Get on a call list with the major re-sellers telling them exactly what you want and know ahead of time what you want. If they call and you don't jump on a good deal right then it will probably be gone by the time you make up your mind.
For a small contract make sure it is not stripped of points. If your first points are coming in late in 2008 it will be late 2009 before you can actually plan a vacation based on your few points.
Summer, though a high point cost, is less busy for DCV, so home resort is not as important, so you can look for cheaper points. OKW has the cheapest rooms points wise, cheap points, and low maintenance fees (fees will end up costing way more than the points themselves over the length of the contract). BWV has some other cheap rooms, but those are few and in high demand, so you may want to buy there if you want to plan vactions around the cheaper point rooms there. SSR has a contract that lasts 15 years longer than the other resorts, which may or may not be important to you (it also has the lowest dues). AKV is so new it will be a while before it is available for resale.
Remember that you can add on to any resort through Disney once you are a member - so if you start with a 50 point contract at OKW you can add on 25 points at a time at AKV if you want to.