Cape Dory 30 or S2 9.2??
When I look at the choices of boats you are asking about I respectfully suggest that you need to take a bit more time before you buy a boat to figure out how you will be sailing and what you really want from a boat. These 3 boats just about could not be further away from each other on the spectrum of 30 or so foot boats. The J-30 is an older style race boat offering good (not great) performance and good (not great) accomodations. They are at best fast cruisers and have the compromises that come with being biased toward speed and being designed in the late 1970''s. The S2-9.2 was a mediocre boat in all regards. By mediocre I mean there is noting great about them but there is noting terrible either. I personnally have spent a lot of time around these boats and I don''t like the way they are built or detailed. The Cape Dory represents another extreme. These are boats that are biased toward being very traditional. Being very traditional comes with a high price as well. They are cramped down below, have a very uncomfortable cockpit underway and compared with a modern design they are painfully slow. In most areas of the Atlantic U.S. coast this kind of slow speed is a real disadvantage in that there are fewer places that you can get to in a day and it means a lot more motoring.
More to the point, if you are considering these three possibilities it means that you have not narrowed down you search criteria and come to an understanding of the type of sailing that you plan to do and what attributes you are looking for in a boat. I suggest that you take a break in your search and spend as much time as you can getting aboard and perhaps sailing on different types of boats. Keep notes on how each boat sailed and try to categorize its characteristics. Talk to a lot of people. When you are done you should be able to simply state more about your preferences in a boat,(i.e. fin keel, post hung rudder, good light air performance, moderate beam, aft head; or perhaps Salty lines, full keel, snug rig, narrow beam, long overhangs) and know why these will work for you.
This is a lousy media for conveying ideas such as these. I assure you I am not trying to put you down or be patronizing in any way but you really should do more homework and in the end I think you will enjoy the boat that you buy a lot more and keep her longer.