Let's say Bamburgh Castle is my base, what do I do for water and food? Is there a well? Could you drink that water straight or would you need to boil it?
It would be trade I reckon. Money is only valuable because we think it is, after an apocalypse it would be worthless. The only things that might be used as currency would have to have another use to. At least until society was reestablished.
Slaves would be very valuable actually. Bet there would be gangs of slavers roaming around not too long after the event. That's why you would need to group together, strength in numbers.
Heroin not so much. Most of the smack heads would probably be dead pretty quick. Tobacco though would probably be as close to currency as you would get.
Heroin's just about the best painkiller we have access to. I'd certainly want some for myself if I ever found myself with a recently-bitten limb in need of amputation.
Would you all be able to kill someone that hadn't turned? Context is important obviously but do you think you could? How dangerous would the assumed threat have to be?