I was just recently in the same boat as you. I was sure I wanted to join DVC but it was my Dh that needed the convincing. Do you have the DVC packet that included the dvd? If not, you can watch the dvd on your computer. Below is the link. You'll see it listed on the right hand side of the page.
http://dvc.disney.go.com/dvc/index
We watched it together and it made a big difference. More importantly, you need to be in the right financial frame of mind. It is a large purchase as I am sure you know so you want to make sure it's not something that could a financial strain on your budget. Although you will save money on your accomodations, there are still plane tickets, park tickets and food to buy--all of which needs to be accounted for when making your decision. If it's realistic that you will only go once every other year, then it might be wise to figure out exactly how many points you need and buy half of that amount--giving you the total you need every other year using the banking system. You may need less points than you think and can find a nice small resale contract. If plans change and you need more points, you can always buy more tickets via and "add on".
One thing I did do to help DH decide was make a spread sheet showing him different ways we could use our points. For example, booking a shorter trip in 07, banking a few points into the next year then getting a large villa in 08 to bring along family. To me, being able to treat "mom & dad" was important and I think it helped sell DH too. It also helps if your DH really enjoys Disney.
Like the above posters mentioned, the friends & family deal offered right now, but only until 1/20 is the best deal SSR has seen in a long time. Sure, there will be other incentives, but non better than $15 off per point--at least not in the near future.
Best of luck with your decision. You came to the right place to ask your questions. You will find veteran DVC owners with lots of helpful information--all of which you can take back to your DH to impress him with your knowledge!
Blakely