I say if you like the bass you should get it. I have let two wonderful P-Basses slip through my hands in the past and I wish I could have the opportunity to buy either right now.
That having been said, I disagree that the finish cracks on the headstock are caused by overtightened tuners. The tuners are held in by 4 tiny screws on the back side. The metallic rings on the string side are simply bushings. They are pressed into place and are pretty much permanently installed once placed. They are not adjustable hence they aren't tighten-able. There are some makes of tuners that the bushings serve double duty as the retaining fasteners also. The bushing is a big nut. That type of tuner can cause finish and even mechanical damage if overtightened and often is because of the misleading size of the nut which suggests it needs to be reefed down. it doesn't need to be. I don't see that happening with the stock tuners that are installed on this bass.
I'm wondering if maybe somebody removed the bushings and either reinstalled them incorrectly or installed improperly sized replacements and the damaged finish occurred. Another thought is that the bass took a hard enough face-down fall that the upper 3 tuners were jammed toward the end of the neck causing the damage via the bushings. Or maybe a slip out of one of the wall hangars that grabbed the tuners on the way down. To me that makes more sense than anything else. I would definitely ask more questions and look much closer at this situation. Ask to remove a couple of the strings, remove tuners, lift the bushings up, and look for damage. Check the tuners for bent posts which will tell the story like skid marks at an accident scene. It may be nothing or it may be a big problem in the making. Be sure it is nothing before getting in too deep.
Rock it!! 
