Not sure if this is a bug or a feature, but the semi-detached house has a cabinet in the front room of the occupied house (right behind the trading guy) that has a wardrobe full of interesting items (including food) every time I went there. It could be a bug, or it could be the private storage of the trader which naturally replenishes as he trades. Either way, I had easy access through the underground tunnel, popping up right into that room, filling up my backpack with the best stuff from that wardrobe, and running home before midnight. Repeat as needed.

Same thing happened in the garage until I completely cleaned it out. Keep in mind that this tends to trigger aggression in the NPCs. Once they realize that they're getting robbed they'll attack you on sight and will never stop.

Very good point. I have decided it is not worth it to rob from the garage, as the trading is just insanely good, and the garage owner replenishes his stock continually. If you run out of meds to trade with him, you can always trade one weapon part for 32 materials. :P