Look over the trailer. Check tires for wear and cracks. Pull a bearing cover and check. Check wiring and that lights work. Trailer title.
Check bottom of boat for wear, dents, repairs, ect. Look over transom good. Some have wood inside the transom that can rot. Soft spots on the floor to some extent should be expected on a older boat and not to hard to fix. A soft transom or leak in the bottom would be a bigger concern.
Test run that motor. How does it start, idle, troll, get on plane, run wide out, turn, ect. Any weird vibrations or noises? Watch the transom for movement when getting up on plane. Does it turn hard? Turn it on and off a few times. Check date on battery. Check prop. Look at lower until for any repairs.
If this all seems to go well and you are serious about buying the boat make sure and check the lower unit oil.
I havent looked at boats for a while but that seems like a decent price if that one is in good shape. Leaves you a few dollars for working on it. Would imagine no make how good of shape it is in there will be some things that need to be done or you just want to do to it.