Well...the first boat being in Maine might present some problems for you as it is not trailerable and would have to be professionally moved or sailed to Philly. Annapolis is doable with an outboard engine if need be.
Knowing the Catalina 27 pretty well...I would tell you that even at a $5k asking price a C27 will generally need a good bit of work to get back to fully functioning Bristol condition and provide plenty of summer fun. When you get down into the $3K range...you are generally looking at real project boats with significant issues. For example...if that Atomic 4 needs rebuilding you are looking at more than the cost of the boat.
Don't limit your search to catalinas...I love 'em but for your purposes..but hunters in the same price range and vintage would do just as well.
Ultimately, you'll want to have whatever boat you buy surveyed professionally to avoid serious hidden problems but the first step if finding a boat that fits your budget and appeals to YOU. That means finding a few in the ads and going to look at them and keeping your checkbook in your pocket till you have a feel for what you get for your money!