We only have 150 points, too, and we "joined" in 2001. So far - we've had 7 nights in a one bedroom at HHI (9/02) and 7 nights in a 2 bedroom at VWL (5/03). Our HHI was almost entirely covered (if not in full, I can't remember) by our MB points (if I remember right we bought in June with a Dec. use year but still got a full year's points??? Can't remember exactly). Our VWL trip required us to borrow a few points from next year. But this is where use year (ours is December) seems to work really well for us. Even though we'll borrowing for a December '04 cruise, in Dec. '05 we'll have the ability to borrow from the next year again. When we bought 150 points we thought realistically we'd probably get a week's vacation every 1 1/2 years, but if you're not afraid to borrow and play around with the points, you can vacation every year and not just in a studio.
This works well for the time being ... an add on is definitely in the future though.