We have gone the same route that you are considering. We purchased a 25 point contract to get into the system. We then added a 55 point contract direct through Disney. Our goal is to have 3 55 point contracts at a minimum.
Some advantages:
1. We will not have to finance and will pay off each add on as we do them.
2. If we need to sell some points, we can easily sell a small contract. If we owned one large contract for 165 then we would have to sell the whole contract and could not split it up.
3. We have 3 children. When it comes time to inherit, if we own one large contract, they can only inherit as co-owners of the one contract. With the 3 separate contracts we can have them each inherit their own contract.
Some disadvantages:
1. Since the minimum purchase direct through Disney is 150 points, you do need to go the resale route for at least your initial contract. Not necessarily a disadvantage, but buying resale is more timeconsuming.
2. Small contracts are popular and can be difficult to find. They are usually snapped up really quick, rarely making it to website listings. Best bet is to contact resellers and let them know what you are looking for. I also suggest to keep calling, so they don't forget about you.
3. Since the contracts are so popular, there really is no negotiations on the price. In fact, in order to make sure a contract gets past Disney's ROFR it may be a good idea to pay more than the asking price sometimes. A reputable seller should have a good idea what price should make it through ROFR, although nothing is guaranteed.
4. Disney has been ROFRing small contracts for non members like crazy, so the price per point on your first contract will be very high compared to purchasing a larger contract. The ROFR process is timeconsuming and if Disney does ROFR your contract, then you are back to the beginning having to find another small contract and so forth. It took us 2 tries to get past ROFR.
5. Points are points at the 7 month mark. However, if you want to take advantage of the 11 month booking window and have more than one contract, you need to make sure they are all at the same resort. If they are from different resorts, you can have the 11 month booking advantage at different resorts, but you can only book at 11 months up to the number of points you own at that resort. Some people do this and then take advantage of banking and borrowing to use 3 years of points for an 11 month reservation. This is not really a disadvantage, just a potential complication that you should be aware of.
Good Luck!