Hi Coldnorth,
I too was worried about being committed every year. (Actually the expenses that come w/ it, airfare, park tix, food). I brought 180 points.
I stay in a one bedroom for 270 points (180 + 90 borrowed)the fist year. The second year in a one bedroom 270 points (90 + 180 borrowed) Do a non WDW vacation in year three. And start the 2 year on one year off all over again. Of course, this may change due to the flexability of the thing. As a matter of fact, I secured a one bedroom this year w/ a standard view which is only 222 points. I can use those extra points in many creative ways. (stay one less night and use a 2 bedroom or go my off year in a studio) The idea is to plan, but also know there is flexability.
good luck.
Dave