So. We just finished the very emotive story of Abraham nearly sacrificing Isaac, and now there is a thematic gap as we "move on" to a different time when Sarah dies. I don't believe this chapter is dated relative to the last event, since the last one is not at some specific time. We can guess that Isaac is maybe 10-15, and since Sarah is 127, that means he is now approximately 26 years old. So maybe 11 years have passed, more or less.
The first thing I notice reading through this is the usage of some arcane terminology, some of which is explained and some isn't. The first term, Kiriath-Arba, is Hebron, as the text notes. It's kinda funny that the text provides this interpolation. It certainly seems to imply either a) the original writer knew both terms, and perhaps knew that one is older than the other, or b) the text first stated the first, and then the interpolation was added later. This second viewpoint is probably the JEDP perspective, though I've never studied it. I don't think the interpolation requires any specific theory though, because basically every commentator (even JEDPists) agree that the OT texts at least loosely draw on some older mythos, whether written or eventually oral, before it was written down. So it is natural that at some point, someone would explain older terms to the "modern" Jewish audience of X00 BCE for whatever value of X. Or alternatively, the writer simply knew the older names for these places/things and knew those names were historical, and chose to use different names in different places. A good modern parallel for this would be Istanbul, also known as Constantinople. Modern readers (and writers) are familiar with both names, and could in certain contexts use them interchangeably. The next term I noticed was "sons of Heth", which is clearly an archaic term for the Canaanites. I'm not familiar with the etymology, and not sure if the etymology is even known.
The rest of the chapter is kinda like the genealogy chapters: fascinating for scholars, kinda boring for theologians or laymen. It is largely an account of Abraham negotiating the purchase of a family burial crypt from some Canaanites. The downside of this passage is that it does little or nothing to advance the general storyline, and God does not intervene in any stated way so it is not particularly spiritual in nature. The upside is that it gives us yet another vantage point of Abraham's character, from the more mundane side of barter.
Abraham has just lost Sarah and is clearly grieving.
Note that the generous offer (I will give you this field for free) is considered a conventional form, and was not intended literally. That is, he was just being polite and it was not supposed to be accepted. The rest of the pleasantries, the bowing, the "my lords" were also conventional. Not to say it's all bad, I personally prefer pleasant conventions to unpleasant conventions. But that is what's going on.
Two things are somewhat strange here. The first is that Abraham does not barter him down. This would have been expected, and from what I've read, Abraham most likely overpaid for the plot of land by a substantial amount. The other strange thing is that they used the merchants' scales. Well, maybe it's not quite "strange", but it is noteworthy. The merchants' scales would generally be much less trustworthy than the royal scales, because they were much less regulated. It is fairly normal to have "bad measurements" to try to exploit others by making their silver appear to weigh less, therefore costing them more.
To be fair, I'm not sure where or if royal scales even existed at this time, so maybe merchants' scales are the only option. I don't know.
Another cultural note (and this shows up often): sitting at the gates is a sign of respect and dignity. This is where the elders or leaders of a city would spend their time. This is also where legal transactions usually happen, because for a legal transaction you need witnesses, and generally the most respected elders make the most reliable witnesses (or if not trustworthy, at least the most trusted).
The last thing I find interesting about this passage is that this is the first (recorded) moment of Abraham owning land in the promised land. I see this as like a first step in the greater promise that he was given by God, just like the birth of Isaac was a first step towards the greater "father of nations". Just as Abraham only sees his one promised son during his lifetime, he also only sees this small, overpriced patch of land, when he had been promised the entire land as far as his eyes could see. It's small beginnings.