Beware of this, unless you're ready and willing to fully test the bass when you collect it (including truss rod adjusting), and does the seller have an amp to try it with? Or can you take your own? Are you allowed to make a noise at the seller's home? Or are you prepared to take the bass back there if you find it's not right once you get it home?
It happened to me like this: I arrived at the very posh house as it was getting dark and spitting with rain... the homeowner (dad) was hovering around outside, clearly concerned about whomever the heck was turning up at his house...
Once I'd done a slightly awkward meet and greet with the father, then the seller (teenager) and his mum , I did a quick visual check on the bass as they all watched me play a few quiet notes via the lad's practice amp, before I thanked them, paid cash and left. The bass looked minty enough, and the controls worked OK.
Next day at home, I realised the TR adjuster was knackered when I attempted to tweak it.
Now, I may be an old softie, but I don't think the young lad was aware of the fault. He seemed so pleased about selling the bass, and it wasn't expensive, so I really couldn't be bothered with complaining and negotiating with his mum, and returning it the 30-odd miles.
Turned out that the TR adjuster was not only rounded out, but also seized solid on the TR, so it snapped when I used the 'last resort' (an easy-out)... so the neck was (is) firewood unless I manage to open it up and change the TR one day.
So to sum up my thoughts -- P&P would have been a whole lot better. I probably won't be doing the 'collection only' thing again.