First hi-tech is good, but start local (saves the cost of transportation to go look at each boat and transport to get it from far away.)
Go to your local marinas repair yards and poke around looking for boats that have been sitting for a long while. Better yet, look around and see what boats you see sitting in driveways with old faded for sale signs on them and don't be afraid to inquire. Some of the best deals are right around the corner; some don't last long; others it's sad in a way how cheap you can pickup a hull that someone was going to rebuilt the engine but ran out of steam.
What specific boat or are there a few boats you are looking for? Make a list of what you really like and google, google, google. You'll find more boats with issues than in perfect condition if you're looking at bargain prices. You can always take apart whatever engine with issues comes with it and see if you can rebuild or part it when you have time & get a few hundred back.