I would suggest you look at the points chart for Wyndham properties, this will give you an idea of the amount of points you would need to book a unit of your liking. Once you know this, then that is the least amount of points you should consider buying. If you want to try the system, is better to rent points from an owner and test the system this way.
The problem in buying a small contract, and then adding another contract, is that you would have two or more closing costs. You would still have to pay full yearly Wyndham membership fee on the small contract, and if you decide you did not like it, you would have to pay closing cost again to sell them or give them away. Also, do not buy an EOY as your fist purchase, as membership fees are paid yearly.
My last bid of advice is to know where you want to vacation. Wyndham has many properties, and probably the largest vacation club, however, they have more properties on the East Coast. So review, compare, and research Wyndham and any other club, because you may find a club that suits you better. And you can always get answers here.
Good luck!