man, that guy certainly doesn't look like it woudl leak a gallon. On thing i have noticed is that people do tend to think there is more water than there really is. I've come back from sailing and taken out the plugs to let some water drain and had my crew(usually a newer to sailing person) go "Holy cow id leaks gallons" when its really only a cup or too. Its looks like more as its comes out. Just check everything thats already been mentioned, re-pack the bearing on the trailer and make an offer. Lowball, you never know how long they have been trying to sell. Sometimes boats just don't move and the owner will dang near take anything.(Of course as an owner recently trying to sell an older cat i have had no experience with this ;-)