By using the banking/borrowing feature you can purchase a smaller contract, say 75 points. Then you can bank a year (ie...2008 into your 2009 use year). Then in 2009 you will be able to use 75pts from 2008 and 75 points from 2009 for a total of 150 points. This would allow you to have nice accomodations every other year and keep your expenses(ie...yearly maintainance fees) to a minimum.
You could also bank 2008 and borrow 2010 points and have available 225 for 2009 if you need additional points. You may only bank points for one year and if they are not used in the following use year you will lose them.
These boards are full of info and you should be able to spend some time here and find out anything you need to know about how the process works.