I don't think you guys get it (and nor do I actually).
You can steal (once) based on how good you are at it. The value and weight is based on the points you put into Thievery rather than Lucky Star or Loremaster or Perception or whatever. After that the NPC is more cautious (but here is the mistake) only with you. So you can then go and steal again from him/her with all your other characters by passing over your gloves. They aren't generally more cautions.
OK you could argue "don't steal from poor people in a prison". That is OK. It is an argument.
Why do they sell books that cost 250 then when they only have 13 gold (like the Hydro guy in the fort)? It took me a long time to realise my offer was unacceptable ("you say 250, I'll give you 200 how about that?") that it was not my offer that mattered but that I had to pay whatever they asked to the penny.
You offer 249 for a 250 item and they get upset. Do it repeatedly and they get more upset. And that is from someone with only 13 gold in their pocket. Persuasion should have an input here.
Honestly if they are pretending to be poor and turning down a reasonable offer then they are hiding something and you may as well steal from them. In the last game you could sneak a loaf of bread or a teleport crysal into their pocket for later use.
There is something up here but I don't know what it is.
